Americium thermodynamic data for the EQ3/6 database

International Nuclear Information System (INIS)

Kerrisk, J.F.

1984-07-01

Existing thermodynamic data for aqueous and solid species of americium have been reviewed and collected in a form that can be used with the EQ3/6 database. Data that are important in solubility calculations for americium at a proposed Yucca Mountain nuclear waste repository were emphasized. Conflicting data exist for americium complexes with carbonates. Essentially no data are available for americium solids or complexes at temperatures greater than 25 0 C. 17 references, 4 figures

Status of Americium-241 recovery at Rocky Flats Plant

International Nuclear Information System (INIS)

Knighton, J.B.; Hagan, P.G.; Navratil, J.D.; Thompson, G.H.

1981-01-01

This paper is presented in two parts: Part I, Molten Salt Extraction of Americium from Molten Plutonium Metal, and Part II, Aqueous Recovery of Americium from Extraction Salts. The Rocky Flats recovery process used for waste salts includes (1) dilute hydrochloric acid dissolution of residues; (2) cation exchange to convert from the chloride to the nitrate system and to remove gross amounts of monovalent impurities; (3) anion exchange separation of plutonium; (4) oxalate precipitation of americium; and (5) calcination of the oxalate at 600 0 C to yield americium oxide. The aqueous process portion describes attempts to improve the recovery of americium. The first part deals with modifications to the cation exchange step; the second describes development of a solvent extractions process that will recovery americium from residues containing aluminium as well as other common impurities. Results of laboratory work are described. 3 figures, 6 tables. (DP)

Americium removal from nitric acid waste streams

International Nuclear Information System (INIS)

Muscatello, A.C.; Navratil, J.D.

1986-01-01

Separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve americium removal from nitric acid (7M) waste streams generated by plutonium purification operations. Partial neutralization of the acid waste followed by solid supported liquid membranes (SLM) are useful in transferring and concentrating americium from nitrate solutions. Specifically, DHDECMP (dihexyl-N,N-diethylcarbamoylmethylphosphonate) supported on Accurel polypropylene hollow fibers assembled in modular form transfers >95% of the americium from high nitrate (6.9M), low acid (0.1M) feeds into 0.25M oxalic acid stripping solution. Maximum permeabilities were observed to be 0.001 cm/sec, consistent with typical values for other systems. The feed:strip volume ratio shows an inverse relationship to the fraction of metal ion transferred. Cation exchangers may be used to concentrate americium from the strip solution. Furthermore, O0D (iB)CMPO (or CMPO) (octylphenyl-N-N-diisobutylcarbamoylmethylphosphine oxide) has been tested in an extraction chromatography mode. Preliminary results show CMPO to be effective in removing americium if the feed is neutralized to 1.0M acidity and iron(III) is complexed with 0.20M oxalic acid. 3 figs

Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

Energy Technology Data Exchange (ETDEWEB)

Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-06-22

Acqueous Chloride mission is to recover plutonium and americium from pyrochemical residues (undesirable form for utilization and storage) and generate plutonium oxide and americium oxide. Plutonium oxide is recycled into Pu metal production flowsheet. It is suitable for storage. Americium oxide is a valuable product, sold through the DOE-OS isotope sales program.

Biosorption of americium by alginate beads

International Nuclear Information System (INIS)

Borba, Tania Regina de; Marumo, Julio Takehiro; Goes, Marcos Maciel de; Ferreira, Rafael Vicente de Padua; Sakata, Solange Kazumi

2009-01-01

The use of biotechnology to remove heavy metals from wastes plays great potential in treatment of radioactive wastes and therefore the aim of this study was to evaluate the biosorption of americium by alginate beads. Biosorption has been defined as the property of certain biomolecules to bind and remove selected ions or other molecules from aqueous solutions. The calcium alginate beads as biosorbent were prepared and analyzed for americium uptaking. The experiments were performed in different solution activity concentrations, pH and exposure time. The results suggest that biosorption process is more efficient at pH 4 and for 75, 150, 300 Bq/mL and 120 minutes were necessary to remove almost 100% of the americium-241 from the solution. (author)

Recycling of americium

International Nuclear Information System (INIS)

Hagstroem, Ingela

1999-12-01

Separation of actinides from spent nuclear fuel is a part of the process of recycling fissile material. Extracting agents for partitioning the high level liquid waste (HLLW) from conventional PUREX reprocessing is studied. The CTH-process is based on three consecutive extraction cycles. In the first cycle protactinium, uranium, neptunium and plutonium are removed by extraction with di-2-ethylhexyl-phosphoric acid (HDEHP) from a 6 M nitric acid HLLW solution. Distribution ratios for actinides, fission products and corrosion products between HLLW and 1 M HDEHP in an aliphatic diluent have been investigated. To avoid addition of chemicals the acidity is reduced by a tributylphosphate (TBP) extraction cycle. The distribution ratios of elements present in HLLW have been measured between 50 % TBP in an aliphatic diluent and synthetic HLLW in range 0.1-6 M nitric acid. In the third extraction cycle americium and curium are extracted. To separate trivalent actinides from lanthanides a method based on selective stripping of the actinides from 1 M HDEHP is proposed. The aqueous phase containing ammonia, diethylenetriaminepentaacetic acid (DTPA) and lactic acid is recycled in a closed loop after reextraction of the actinides into a second organic phase also containing 1 M HDEHP. Distribution ratios for americium and neodymium have been measured at varying DTPA and lactic acid concentrations and at varying pH. Nitrogen-donor reagents have been shown to have a potential to separate trivalent actinides from lanthanides. 2,2':6,2''-terpyridine as extractant follows the CHON-principle and can in synergy with 2-bromodecanoic acid separate americium from europium. Distribution ratios for americium and europium, in the range of 0.02-0.12 M nitric acid, between nitric acid and 0.02 M terpyridine with 1 M 2-bromodecanoic acid in tert-butylbenzene (TBB) was investigated. Comparison with other nitrogen-donor reagents show that increasing lipophilicity of the molecule, by substitution of

Americium product solidification and disposal

International Nuclear Information System (INIS)

Mailen, J.C.; Campbell, D.O.; Bell, J.T.; Collins, E.D.

1987-01-01

The americium product from the TRUEX processing plant needs to be converted into a form suitable for ultimate disposal. An evaluation of the disposal based on safety, number of process steps, demonstrated operability of the processes, production of low-level alpha waste streams, and simplicity of maintenance with low radiation exposures to personnel during maintenance, has been made. The best process is to load the americium on a cation exchange resin followed by calcination or oxidation of the resin after loading

Uptake of americium-241 by algae and bacteria

Energy Technology Data Exchange (ETDEWEB)

Geisy, J P; Paine, D

1978-01-01

Algae and bacteria are important factors in the transport and mobilization of elements in the biosphere. These factors may be involved in trophic biomagnification, resulting in a potential human hazard or environmental degradation. Although americium, one of the most toxic elements known, is not required for plant growth, it may be concentrated by algae and bacteria. Therefore, the availability of americium-241 to algae and bacteria was studied to determine their role in the ultimate fate of this element released into the environment. Both algae and bacteria concentrated americium-241 to a high degree, making them important parts of the biomagnification process. The ability to concentrate americium-241 makes algae and bacteria potentially significant factors in cycling this element in the water column. (4 graphs, numerous references, 3 tables)

Americium migration in basalt and implications to repository risk analysis

International Nuclear Information System (INIS)

Rickert, P.G.

1980-01-01

Experiments were performed with americium as a minor component in groundwater. Batch adsorption, migration through column, and filtration experiments were performed. It was determined in batch experiments that americium is strongly adsorbed from solution. It was determined with filtration experiments that large percentages of the americium concentrations suspended by the contact solutions in batch experiments and suspended by the infiltrating groundwater in migration experiments were associated with particulate. Filtration was determined to be the primary mode of removal of americium from infiltrating groundwater in a column of granulated basalt (20 to 50 mesh) and an intact core of permeable basalt. Fractionally, 0.46 and 0.22 of the americium component in the infiltrating groundwater was transported through the column and core respectively. In view of these filtration and migration experiment results, the concept of K/sub d/ in the chromatographic sense is meaningless for predicting americium migration in bedrock by groundwater transport at near neutral pH

Recovery and purification of americium from molten salt extraction residues

International Nuclear Information System (INIS)

Navratil, J.D.; Martella, L.L.; Thompson, G.H.

1980-01-01

Americium recovery and purification development at Rocky Flats involves the testing of a combined anion exchange - bidentate organophosphorus liquid - liquid extraction or extraction chromatography process for separating americium from molten salt extraction residues. Laboratory-scale and preliminary pilot-plant results have shown that americium can be effectively recovered and purified from impurity elements such as aluminum, calcium, magnesium, plutonium, potassium, sodium, and zinc. The purified americium oxide product from the liquid - liquid extraction process contained greater than 95% AmO 2 with less than 1% of any individual impurity element

Transmutation of Americium in Fast Neutron Facilities

International Nuclear Information System (INIS)

Zhang, Youpeng

2011-01-01

In this thesis, the feasibility to use a medium sized sodium cooled fast reactor fully loaded with MOX fuel for efficient transmutation of americium is investigated by simulating the safety performance of a BN600-type fast reactor loaded with different fractions of americium in the fuel, using the safety parameters obtained with the SERPENT Monte Carlo code. The focus is on americium mainly due to its long-term contribution to the radiotoxicity of spent nuclear fuel and its deterioration on core's safety parameters. Applying the SAS4A/SASSYS transient analysis code, it is demonstrated that the power rating needs to be reduced by 6% for each percent additional americium introduction into the reference MOX fuel, maintaining 100 K margin to fuel melting, which is the most limiting failure mechanism. Safety analysis of a new Accelerator Driven System design with a smaller pin pitch-to-diameter ratio comparing to the reference EFIT-400 design, aiming at improving neutron source efficiency, was also performed by simulating performance for unprotected loss of flow, unprotected transient overpower, and protected loss-of-heat-sink transients, using neutronic parameters obtained from MCNP calculations. Thanks to the introduction of the austenitic 15/15Ti stainless steel with enhanced creep rupture resistance and acceptable irradiation swelling rate, the suggested ADS design loaded with nitride fuel and cooled by lead-bismuth eutectic could survive the full set of transients, preserving a margin of 130 K to cladding rupture during the most limiting transient. The thesis concludes that efficient transmutation of americium in a medium sized sodium cooled fast reactor loaded with MOX fuel is possible but leads to a severe power penalty. Instead, preserving transmutation rates of minor actinides up to 42 kg/TWh th , the suggested ADS design with enhanced proton source efficiency appears like a better option for americium transmutation

Procedure for the analysis of americium in complex matrices

International Nuclear Information System (INIS)

Knab, D.

1978-02-01

A radioanalytical procedure for the analysis of americium in complex matrices has been developed. Clean separations of americium can be obtained from up to 100 g of sample ash, regardless of the starting material. The ability to analyze large masses of material provides the increased sensitivity necessary to detect americium in many environmental samples. The procedure adequately decontaminates from rare earth elements and natural radioactive nuclides that interfere with the alpha spectrometric measurements

Preparation of americium metal of high purity and determination of the heat of formation of the hydrated trivalent americium ion

International Nuclear Information System (INIS)

Spirlet, J.C.

1975-10-01

In order to redetermine some physical and chemical properties of americium metal, several grams of Am-241 have been prepared by two independent methods: lanthanum reduction of the oxide and thermal dissociation of the intermetallic compound Pt 5 Am. After its separation from excess lanthanum or alloy constituent by evaporation, americium metal was further purified by sublimation at 1100 deg C and 10 -6 Torr. Irrespective of the method of preparation, the americium samples displayed the same d.h.c.p. crystal structure. As determined by vacuum hot extraction, the oxygen, nitrogen and hydrogen contents are equal to or smaller than 250, 50 and 20 ppm, respectively. The heats of solution of americium metal (d.c.h.p. structure) in aqueous hydrochloric acid solutions have been measured at 298.15+-0.05K. The standard enthalpy of formation of Am 3+ (aq) is obtained as -616.7+-1.2 kJ mol -1 [fr

Chemistry of americium

Energy Technology Data Exchange (ETDEWEB)

Schulz, W.W.

1976-01-01

Essential features of the descriptive chemistry of americium are reviewed. Chapter titles are: discovery, atomic and nuclear properties, collateral reading, production and uses, chemistry in aqueous solution, metal, alloys, and compounds, and, recovery, separation, purification. Author and subject indexes are included. (JCB)

Comparative behavior of americium and plutonium in wastewater

International Nuclear Information System (INIS)

Tsvetaeva, N.E.; Filin, V.M.; Ragimov, T.K.; Rudaya, L.Y.; Shapiro, K.Y.; Shcherbakov, B.Y.

1986-01-01

This paper studies the behavior of trace americium and plutoniumin wastewater fed into purification systems. Activities of the elements were determined on a semiconductive alpha-ray spectrometer. the distributio nonuniformity, or heterogeneity, of americium and plutonium per unit volume of wastewater was determined quantitatively before and after passage through filter papers. The two elements were found to be in a colloidal or pseudocolloidal state in the original wastewater sample at pH 6. On acidifying the wastewater from pH 4 to 1 M nitric acid the americium passed quantitatively into the water phase but the most plutonium remained in the colloidal or pseudocolloidal state. the plutonium also passed quantitatively into the water phase in wastewater at a 1 M nitric acid acidity but only after a prolonged (12-day) hold. A knowledge of the heterogeneity of plutonium and americium in wastewaters made it possible to quickly distinguish their state, i.e., colloidal, pseudocolloidal, or in true solution

Formation of americium and europium humate complexes

International Nuclear Information System (INIS)

Minai, Y.; Tominaga, T.; Meguro, Y.

1991-01-01

Binding constants of americium and europium with a humic acid were determined to study if complex formation of trivalent actinide-humates affects dissolved species of the actinides in hydrosphere. The purified humic acid was characterized by means of UV-vis, IR, and pH titration, indicating high carboxylate capacity and low aromaticity. Binding constants of americium and europium humates were determined at pH 4.6 and 6.0 by solvent extraction using 241 Am or 152 Eu as a tracer. The binding constants for americium-humate obtained preliminarily suggest that complexes with humic acid are not negligible in speciation of trivalent actinides in hydrosphere. The obtained binding constants were nearly identical with those determined previously by the same procedures, but with humic acids of different origin and compositions. (author)

PROCESS FOR SEPARATING AMERICIUM AND CURIUM FROM RARE EARTH ELEMENTS

Science.gov (United States)

Baybarz, R.D.; Lloyd, M.H.

1963-02-26

This invention relates to methods of separating americium and curium values from rare earth values. In accordance with the invention americium, curium, and rare earth values are sorbed on an anion exchange resin. A major portion of the rare earth values are selectively stripped from the resin with a concentrated aqueous solution of lithium chloride, and americium, curium, and a minor portion of rare earth values are then stripped from the resin with a dilute aqueous solution of lithium chloride. The americium and curium values are further purified by increasing the concentration of lithium chloride in the solution to at least 8 molar and selectively extracting rare earth values from the resulting solution with a monoalkylphosphoric acid. (AEC)

Plutonium and Americium Geochemistry at Hanford: A Site Wide Review

Energy Technology Data Exchange (ETDEWEB)

Cantrell, Kirk J.; Felmy, Andrew R.

2012-08-23

This report was produced to provide a systematic review of the state-of-knowledge of plutonium and americium geochemistry at the Hanford Site. The report integrates existing knowledge of the subsurface migration behavior of plutonium and americium at the Hanford Site with available information in the scientific literature regarding the geochemistry of plutonium and americium in systems that are environmentally relevant to the Hanford Site. As a part of the report, key research needs are identified and prioritized, with the ultimate goal of developing a science-based capability to quantitatively assess risk at sites contaminated with plutonium and americium at the Hanford Site and the impact of remediation technologies and closure strategies.

Investigation of factors affecting the quality of americium electroplating

International Nuclear Information System (INIS)

Trdin, M.; Benedik, L.; Samardžija, Z.; Pihlar, B.

2012-01-01

Four different electrolyte solutions were used in the electrodeposition of americium and their influences on the quality of the thin layer of deposited americium isotopes in combination with three different cathode disc materials were investigated. The relations between alpha spectral resolution and disc surface properties were established. - Highlights: ► Compared alpha spectra of americium radioisotopes obtained by electrodeposition. ► Various cathode materials and electrolyte solutions were used. ► Homogeneity and peak area resolution were investigated. ► Electron microscope images show surface structure of electrodeposited material.

Measurement of plutonium and americium in molten salt residues

International Nuclear Information System (INIS)

Haas, F.X.; Lawless, J.L.; Herren, W.E.; Hughes, M.E.

1979-01-01

The measurement of plutonium and americium in molten salt residues using a segmented gamma-ray scanning device is described. This system was calibrated using artificially fabricated as well as process generated samples. All samples were calorimetered and the americium to plutonium content of the samples determined by gamma-ray spectroscopy. For the nine samples calorimetered thus far, no significant biases are present in the comparison of the segmented gamma-ray assay and the calorimetric assay. Estimated errors are of the order of 10 percent and is dependent on the americium to plutonium ratio determination

Americium separations from high salt solutions

International Nuclear Information System (INIS)

Barr, Mary E.; Jarvinen, Gordon D.; Schulte, Louis D.; Stark, Peter C.; Chamberlin, Rebecca M.; Abney, Kent D.; Ricketts, Thomas E.; Valdez, Yvette E.; Bartsch, Richard A.

2000-01-01

Americium (III) exhibits an unexpectedly high affinity for anion-exchange material from the high-salt evaporator bottoms solutions--an effect which has not been duplicated using simple salt solutions. Similar behavior is observed for its lanthanide homologue, Nd(III), in complex evaporator bottoms surrogate solutions. There appears to be no single controlling factor--acid concentration, total nitrate concentration or solution ionic strength--which accounts for the approximately 2-fold increase in retention of the trivalent ions from complex solutions relative to simple solutions. Calculation of species activities (i.e., water, proton and nitrate) in such concentrated mixed salt solutions is difficult and of questionable accuracy, but it is likely that the answer to forcing formation of anionic nitrate complexes of americium lies in the relative activities of water and nitrate. From a practical viewpoint, the modest americium removal needs (ca. 50--75%) from nitric acid evaporator bottoms allow sufficient latitude for the use of non-optimized conditions such as running existing columns filled with older, well-used Reillex HPQ. Newer materials, such as HPQ-100 and the experimental bifunctional resins, which exhibit higher distribution coefficients, would allow for either increased Am removal or the use of smaller columns. It is also of interest that one of the experimental neutral-donor solid-support extractants, DHDECMP, exhibits a similarly high level of americium (total alpha) removal from EV bottoms and is much less sensitive to total acid content than commercially-available material

Transmutation of americium in critical reactors

International Nuclear Information System (INIS)

Wallenius, J.

2005-01-01

Already in 1974, a Los Alamos report suggested that the recycling of higher actinides would be detrimental for the safety of critical reactors. Later investigations confirmed this understanding, and stringent limits on the fraction of minor actinides allowed to be present in the fuel of fast neutron reactors were established. In recent years, and in particular in connection with the generation IV initiative, it has been advocated that recycling of americium in critical reactors is not only feasible, but also a recommendable approach. In the present contribution, it is shown, to the contrary, that introduction of americium into reactors with uranium based fuels deteriorates the safety margin of these reactors to a degree that will not allow consumption of the americium sources present in any economically competitive nuclear fuel cycle. Further, it is shown that uranium and thorium free cores with plutonium based fuels may be designed, that features excellent safety characteristics, as long as americium is not present in the feed. Hence, a closed fuel cycle is suggested, that consists of commercial power production in light water reactors, plutonium burning in uranium and thorium free fast neutron critical reactors, and higher actinide consumption in accelerator driven systems with inert matrix fuel. It is argued that such a fuel cycle (being a refinement of the Double Strata fuel cycle proposed by JAERI and further developed by M. Salvatores) provides a minimum cost penalty for implementing P and T under realistic boundary conditions. (author)

Sorption of americium and neptunium by deep-sea sediments

International Nuclear Information System (INIS)

Higgo, J.J.W.; Rees, L.V.C.; Cronan, D.S.

1983-01-01

The sorption and desorption of americium and neptunium by a wide range of deep-sea sediments from natural sea water at 4 0 C has been studied using a carefully controlled batch technique. All the sediments studied should form an excellent barrier to the migration of americium since distribution coefficients were uniformly greater than 10 5 and the sorption-desorption reaction may not be reversible. The sorption of neptunium was reversible and, except for one red clay, the distribution coefficients were greater than 10 3 for all the sediments investigated. Nevertheless the migration of neptunium should also be effectively retarded by most deep-sea sediments even under relatively oxidizing conditions. The neptunium in solution remained in the V oxidation state throughout the experiments. Under the experimental conditions used colloidal americium was trapped by the sediment and solubility did not seem to be the controlling factor in the desorption of americium. (Auth.)

Factors affecting the retention of methyl iodide by iodide-impregnated carbon

International Nuclear Information System (INIS)

Hyder, M.L.; Malstrom, R.A.

1991-01-01

This paper comprises two sets of studies of methyl iodide retention by iodide-impregnated carbon. In the first of these, the retention of the methyl iodide on the carbon surface and its subsequent evolution were observed directly by a technique of combustion and phosphorescence. In the second, the methyl iodide retention in a standard test was compared with surface area measurements and the concentration of unreacted iodine. A correlation among these parameters was identified and characterized. Carbon quality was varied through the selection of used material with differing service histories. Air from the Savannah River Site reactor buildings is vented through carbon beds for control of radioiodine before release to the atmosphere. The carbon used is North American Carbon Co. type GX-176 coconut shell carbon impregnated with 1% triethylenedimaine (TEDA) and 2% potassium iodide by weight. Replacement intervals for the carbon have been as long as thirty months. Analysis of samples withdrawn at much shorter times has shown that the TEDA is lost after a few months, and the performance of the carbon for methyl iodide retention is dependent on the iodide impregnant. Efficient methyl iodide retention is not a requirement for carbon in this service; however, methyl iodide retention as measured by the ASTM Test D3803 (method B) has been found to correlate well with other desirable properties of the carbon such as radiation stability. The studies undertaken here were intended to shed light on the changes taking place in this carbon during long-term service and to provide a basis for simpler measurements of carbon quality

Supported extractant membranes for americium and plutonium recovery

International Nuclear Information System (INIS)

Muscatello, A.C.; Navratil, J.D.; Killion, M.E.; Price, M.Y.

1987-01-01

Solid supported liquid membranes(SLM) are useful in transferring and concentrating americium and plutonium from nitrate solutions. Specifically, DHDECMP(dihexyl-N,N-diethylcarbamoylmethylphosphonate) supported on Accurel or Celgard polypropylene hollow fibers assembled in modular form transfers >95% of the americium and >70% of the plutonium from high nitrate (6.9 M), low acid (0.1 M) feeds into 0.25 M oxalic acid stripping solution. Membranes supporting TBP (tri-n-butylphosphate) also transfer these metal ions. Maximum permeabilities were observed to be 1 x 10 -3 cm sec -1 , similar to the values for other systems. The feed:strip volume ratio shows an inverse relationship to the fraction of metal ion transferred. Cation exchangers may be used to concentrate americium from the strip solution

Recovery of americium-241 from aged plutonium metal

International Nuclear Information System (INIS)

Gray, L.W.; Burney, G.A.; Reilly, T.A.; Wilson, T.W.; McKibben, J.M.

1980-12-01

About 5 kg of ingrown 241 Am was recovered from 850 kg of aged plutonium using a process developed specifically for Savannah River Plant application. The aged plutonium metal was first dissolved in sulfamic acid. Sodium nitrite was added to oxidize the plutonium to Pu(IV) and the residual sulfamate ion was oxidized to nitrogen gas and sulfate. The plutonium and americium were separated by one cycle of solvent extraction. The recovered products were subsequently purified by cation exchange chromatography, precipitated as oxalates, and calcined to the oxides. Plutonium processng was routine. Before cation exchange purification, the aqueous americium solution from solvent extraction was concentrated and stripped of nitric acid. More than 98% of the 241 Am was then recovered from the cation exchange column where it was effectively decontaminated from all major impurities except nickel and chromium. This partially purified product solution was concentrated further by evaporation and then denitrated by reaction with formic acid. Individual batches of americium oxalate were then precipitated, filtered, washed, and calcined. About 98.5% of the americium was recovered. The final product purity averaged 98% 241 AmO 2 ; residual impurities were primarily lead and nickel

The evolution of hydrogen and iodine by the decomposition of ammonium iodide and hydrogen iodide

International Nuclear Information System (INIS)

Ishikawa, Hiroshi; Nakane, Masanori; Ishii, Eiichi; Uehara, Itsuki; Miyake, Yoshizo

1977-01-01

As a fundamental study on thermochemical production of hydrogen from water, the evolution of hydrogen and iodine from ammonium iodide and hydrogen iodide was investigated. Hydrogen was evolved by the reaction of nickel with ammonium iodide or with hydrogen iodide, and the resulting nickel(II) iodide was decomposed thermally at 600 -- 700 0 C to form nickel. First, the iodination of powdered nickel with ammonium iodide was studied by heating their powder mixture. The maximum yield of hydrogen was obtained at a temperature near 430 0 C. The iodination of powdered nickel with gaseous ammonium iodide or with dry hydrogen iodide gas was also investigated. In this case, coating of nickel particles with a layer of resulting nickel(II) iodide prevented further conversion of nickel and lowered the reaction rate. Such a retardation effect was appreciably lessened by use of carrier. When nickel was supported on such a carrier as ''isolite'', the nickel was converted into nickel(II) iodide easily. In a reaction temperature from 400 to 500 0 C, the rate of reaction between nickel and hydrogen iodide increased slightly with the elevation of the reaction temperature. In the case of ammonium iodide, the reaction rate was higher than that for hydrogen iodide and decreased apparently with the elevation of the reaction temperature, because ammonium iodide decomposed to ammonia and hydrogen iodide. Tests using a fixed bed reactor charged with 8 -- 10 mesh ''isolite''-nickel (30 wt%) were also carried out. The maximum yield of hydrogen was about 80% for ammonium iodide at 430 0 C of reaction temperature and 60% for hydrogen iodide at 500 0 C. (auth.)

Determination of the oxygen-metal-ratio of uranium-americium mixed oxides

International Nuclear Information System (INIS)

Bartscher, W.

1982-01-01

During the dissolution of uranium-americium mixed oxides in phosphoric acid under nitrogen tetravalent uranium is oxidized by tetravalent americium. The obtained hexavalent uranium is determined by constant potential coulometry. The coulombs measured are equivalent to the oxygen in excess of the minimum composition of UO 2 x AmO 1 . 5 . The total uranium content of the sample is determined in a subsequent coulometric titration. The oxygen-metal ratio of the sample can be calculated for a given uranium-americium ratio. An excess of uranium dioxide is necessary in order to suppress the oxidation of water by tetravalent americium. The standard deviation of the method is 0.0017 O/M units. (orig.) [de

1976 Hanford americium-exposure incident: external decontamination procedures

International Nuclear Information System (INIS)

Jech, J.J.; Berry, J.R.; Breitenstein, B.D.

1982-01-01

An accident resulted in the deposition on an injured workman's skin surfaces, in acid-burned areas and in lacerations, of something in excess of 6 mCi americium-241. The external decontamination procedures used, the change in americium content of the skin during the course of treatment, and some of the unusual problems encountered from the extrusion of foreign material and flaking of skin and scar tissue are described

Investigation of factors affecting the quality of americium electroplating.

Science.gov (United States)

Trdin, M; Benedik, L; Samardžija, Z; Pihlar, B

2012-09-01

Four different electrolyte solutions were used in the electrodeposition of americium and their influences on the quality of the thin layer of deposited americium isotopes in combination with three different cathode disc materials were investigated. The relations between alpha spectral resolution and disc surface properties were established. Copyright © 2012 Elsevier Ltd. All rights reserved.

Method of isolation of traces of americium by using the +6 oxidation state properties

International Nuclear Information System (INIS)

Kwinta, Jean; Michel, Jean-Jacques

1969-05-01

The authors present a method to separate traces of americium from a solution containing fission products and actinides. This method comprises the following steps: firstly, the oxidation of americium at the +6 state by ammonium persulfate and carrying over of actinides and III and IV lanthanides by lanthanum fluoride; secondly, the reduction by hydrazine of the oxidized americium and carrying over of the reduced americium by lutetium fluoride; and thirdly, the americium-lutetium separation by selective extractions either with di 2 ethyl hexyl phosphoric acid, or by fractionated elution on an anionic resin column by a mixture of nitric acid and methanol [fr

Americium-241 - ED 4308

International Nuclear Information System (INIS)

Ammerich, M.; Frot, P.; Gambini, D.; Gauron, C.; Moureaux, P.; Herbelet, G.; Lahaye, T.; Le Guen, B.; Pihet, P.; Rannou, A.; Vidal, E.

2012-12-01

This sheet presents the characteristics of Americium-241, its origin, and its radio-physical and biological properties. It briefly describes its use in nuclear medicine. It indicates its dosimetric parameters for external exposure, cutaneous contamination, and internal exposure due to acute contamination or to chronic contamination. It indicates and comments the various exposure control techniques: ambient dose rate measurement, surface contamination measurement, atmosphere contamination. It addresses the means of protection: premise design, protection against external exposure and against internal exposure. It describes how areas are delimited and controlled within the premises: regulatory areas, controls to be performed. It addresses the personnel classification, training and medical survey. It addresses the issue of wastes and effluents. It briefly recalls the administrative procedures related to the authorization and declaration of possession and use of sealed and unsealed sources. It indicates regulatory aspects related to the road transport of Americium-241, describes what is to be done in case of incident or accident (for the different types of contamination or exposure)

dl-Alaninium iodide

Directory of Open Access Journals (Sweden)

Kevin Lamberts

2012-06-01

Full Text Available The crystal structure of dl-alanine hydroiodide (1-carboxyethanaminium iodide, C3H8NO2+·I−, is that of an organic salt consisting of N-protonated cations and iodide anions. The compound features homochiral helices of N—H...O hydrogen-bonded cations in the [010] direction; neighbouring chains are related by crystallographic inversion centers and hence show opposite chirality. The iodide counter-anions act as hydrogen-bond acceptors towards H atoms of the ammonium and carboxy groups, and cross-link the chains along [100]. Thus, an overall two-dimensional network is formed in the ab plane. No short contacts occur between iodide anions.

Dynamic iodide trapping by tumor cells expressing the thyroidal sodium iodide symporter

International Nuclear Information System (INIS)

Dingli, David; Bergert, Elizabeth R.; Bajzer, Zeljko; O'Connor, Michael K.; Russell, Stephen J.; Morris, John C.

2004-01-01

The thyroidal sodium iodide symporter (NIS) in combination with various radioactive isotopes has shown promise as a therapeutic gene in various tumor models. Therapy depends on adequate retention of the isotope in the tumor. We hypothesized that in the absence of iodide organification, isotope trapping is a dynamic process either due to slow efflux or re-uptake of the isotope by cells expressing NIS. Iodide efflux is slower in ARH-77 and K-562 cells expressing NIS compared to a thyroid cell line. Isotope retention half times varied linearly with the number of cells expressing NIS. With sufficient NIS expression, iodide efflux is a zero-order process. Efflux kinetics in the presence or absence of perchlorate also supports the hypothesis that iodide re-uptake occurs and contributes to the retention of the isotope in tumor cells. Iodide organification was insignificant. In vivo studies in tumors composed of mixed cell populations confirmed these observations

Research program on development of advanced treatment technology for americium-containing aqueous waste in NUCEF

Energy Technology Data Exchange (ETDEWEB)

Mineo, Hideaki; Matsumura, Tatsuro; Tsubata, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1996-10-01

A research program was prepared on the development of an advanced treatment process for the americium-containing concentrated aqueous waste in NUCEF, than allows americium recovery for the reuse and the reduction of TRU waste generation. A preliminary analysis was conducted on the separation requirements based on the components estimated for the waste. An R and D strategy was proposed from the view to reduce TRU waste generated in the processing that the highest priority is given on the control of TRU leakage such as americium into the effluent stream after americium recovery and the minimization of salt used in the separation over the decontamination of impurities from americium. The extraction chromatographic method was selected as a candidate technology for americium separation under the principle to use reagents that are functional in acidic conditions such as bidentate extractants of DHEDECMP, CMPO or diamides, considering the larger flexibilities in process modification and possible multi-component separation with compact equipment and the past achievements on the recovery of kg quantities of americium. Major R and D items extracted are screening and evaluation of extractants for americium and plutonium, optimization of separation conditions, selection of denitration method, equipment developments and development of solidification methods of discarded americium after reuse and of various kinds of separation residues. In order to cope these items, four steps of R and D program were proposed, i.e., fundamental experiment in beaker-scale on screening and evaluation of extractants, flowsheet study in bench-scale using simulated and small amount of americium aqueous waste solution to evaluate candidate process, americium recovery test in iron-shielded cell to be installed in NUCEF. It is objected to make recovery of 100g orders of americium used for research on fundamental TRU fuel properties. (J.P.N.)

Decontaminaion of metals containing plutonium and americium

International Nuclear Information System (INIS)

Seitz, M.G.; Gerding, T.J.; Steindler, M.J.

1979-06-01

Melt-slagging (melt-refining) techniques were evaluated as a decontamination and consolidation step for metals contaminated with oxides of plutonium and americium. Experiments were performed in which mild steel, stainless steel, and nickel contaminated with oxides of plutonium and americium were melted in the presence of silicate slags of various compositions. The metal products were low in contamination, with the plutonium and americium strongly fractionated to the slags. Partition coefficients (plutonium in slag/plutonium in steel) of 7 x 10 6 were measured with boro-silicate slag and of 3 x 10 6 with calcium, magnesium silicate slag. Decontamination of metals containing as much as 14,000 ppM plutonium appears to be as efficient as for metals with plutonium levels of 400 ppM. Staged extraction, that is, a remelting of processed metal with clean slag, results in further decontamination of the metal. The second extraction is effective with either resistance-furnace melting or electric-arc melting. Slag adhering to the metal ingots and in defects within the ingots is in the important contributors to plutonium retained in processed metals. If these sources of plutonium are controlled, the melt-refining process can be used on a large scale to convert highly contaminated metals to homogeneous and compact forms with very low concentrations of plutonium and americium. A conceptual design of a melt-refining process to decontaminate plutonium- and americium-contaminated metals is described. The process includes single-stage refining of contaminated metals to produce a metal product which would have less than 10 nCi/g of TRU-element contamination. Two plant sizes were considered. The smaller conceptual plant processes 77 kg of metal per 8-h period and may be portable.The larger one processes 140 kg of metal per 8-h period, is stationary, and may be near te maximum size that is practical for a metal decontamination process

Distribution of uranium, americium and plutonium in the biomass of freshwater macrophytes

Energy Technology Data Exchange (ETDEWEB)

Zotina, T.A.; Kalacheva, G.S.; Bolsunovsky, A.YA. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk (Russian Federation)

2010-07-01

Accumulation of uranium ({sup 238}U), americium ({sup 241}Am) and plutonium ({sup 242}Pu) and their distribution in cell compartments and biochemical components of the biomass of aquatic plants Elodea canadensis, Ceratophyllum demersum, Myrioplyllum spicatum and aquatic moss Fontinalis antipyretica have been investigated in laboratory batch experiments. Isotopes of uranium, americium and plutonium taken up from the water by Elodea canadensis apical shoots were mainly absorbed by cell walls, plasmalemma and organelles. A small portion of isotopes (about 6-13 %) could be dissolved in cytoplasm. The major portion (76-92 %) of americium was bound to cell wall cellulose-like polysaccharides of Elodea canadensis, Myriophyllum spicatum, Ceratophyllum demersum and Fontinalis antipyretica, 8-23 % of americium activity was registered in the fraction of proteins and carbohydrates, and just a small portion (< 1%) in lipid fraction. The distribution of plutonium in the biomass fraction of Elodea was similar to that of americium. Hence, americium and plutonium had the highest affinity to cellulose-like polysaccharides in Elodea biomass. Distribution of uranium in the biomass of Elodea differed essentially from that of transuranium elements: a considerable portion of uranium was recorded in the fraction of protein and carbohydrates (51 %). From our data we can assume that uranium has higher affinity to carbohydrates than proteins. (authors)

Distribution of uranium, americium and plutonium in the biomass of freshwater macrophytes

International Nuclear Information System (INIS)

Zotina, T.A.; Kalacheva, G.S.; Bolsunovsky, A.YA.

2010-01-01

Accumulation of uranium ( 238 U), americium ( 241 Am) and plutonium ( 242 Pu) and their distribution in cell compartments and biochemical components of the biomass of aquatic plants Elodea canadensis, Ceratophyllum demersum, Myrioplyllum spicatum and aquatic moss Fontinalis antipyretica have been investigated in laboratory batch experiments. Isotopes of uranium, americium and plutonium taken up from the water by Elodea canadensis apical shoots were mainly absorbed by cell walls, plasmalemma and organelles. A small portion of isotopes (about 6-13 %) could be dissolved in cytoplasm. The major portion (76-92 %) of americium was bound to cell wall cellulose-like polysaccharides of Elodea canadensis, Myriophyllum spicatum, Ceratophyllum demersum and Fontinalis antipyretica, 8-23 % of americium activity was registered in the fraction of proteins and carbohydrates, and just a small portion (< 1%) in lipid fraction. The distribution of plutonium in the biomass fraction of Elodea was similar to that of americium. Hence, americium and plutonium had the highest affinity to cellulose-like polysaccharides in Elodea biomass. Distribution of uranium in the biomass of Elodea differed essentially from that of transuranium elements: a considerable portion of uranium was recorded in the fraction of protein and carbohydrates (51 %). From our data we can assume that uranium has higher affinity to carbohydrates than proteins. (authors)

Analytical separation of americium and curium, using high performance liquid chromatography

International Nuclear Information System (INIS)

Billon, A.

1978-01-01

Americium and curium are separated on a column of cation exchange resin (Aminex) using hydroxyisobutyric acid (α HIBA) as eluent, at a temperature of 80 0 C. Americium and curium were detected in line using their α emission: the separation was performed in a shielded glove box whose setting-up is given. Finally, the time necessary for a separation is comprised between 30 min and 1 hr. The purity of separated fractions was assayed by mass-spectrometry. An application in the determination of isotopic composition of americium and curium in fuels is described

Preparation of americium source for smoke detector

International Nuclear Information System (INIS)

Ramaswami, A.; Singh, R.J.; Manohar, S.B.

1994-01-01

This report describes the method developed for the preparation of 241 Am source for smoke detector. Americium was electrodeposited from iso-propyl alcohol medium on silver backing. Thin layer of gold (few hundred micro gram thick) was plated on the americium source to make it safe for handling. The thickness of plated gold was such that the alpha radiations from the 241 Am source could escape out of the gold layer and cause ionisation in the surrounding air. The performance of the prepared sources were checked in a smoke detector and was found to be satisfactory and comparable to the imported sources. (author). 1 refs., 2 figs., 1 tab

Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

Energy Technology Data Exchange (ETDEWEB)

Gardner, Kyle Shelton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-09-28

These are a set of slides intended for an information session as part of recruiting activities at Brigham Young University. It gives an overview of aqueous chloride operations, specifically on plutonium and americium purification/recovery. This presentation details the steps taken perform these processes, from plutonium size reduction, dissolution, solvent extraction, oxalate precipitation, to calcination. For americium recovery, it details the CLEAR (chloride extraction and actinide recovery) Line, oxalate precipitation and calcination.

Separation of Americium from plutonium, Annex 3; Prilog 3: Odvajanje amercijuma od plutonijuma

Energy Technology Data Exchange (ETDEWEB)

Cvjeticanin, D; Milic, N; Janicijevic, P; Ratkovic, S [Institute of Nuclear Sciences Boris Kidric, Laboratorija za visoku aktivnost, Vinca, Beograd (Serbia and Montenegro)

1963-12-15

Since there was the possibility of working with plutonium milligram quantities, it was possible to study plutonium with contents of americium, which was expected in the about two years old plutonium solutions. Method for separation of the micro quantities of americium and plutonium was needed as well as a multichannel alpha-pulse analyzer. Method for separation of americium from plutonium by thenol trifluoro-acetone (TTA) and anion exchange was adopted.

Extraction of americium from acid aqueous solutions by diethyl-2-hexyl-pyro-phosphoric acid

International Nuclear Information System (INIS)

Guillaume, Bernard

1971-02-01

After having outlined the interesting properties of americium and the difficulties of its recovery, the author reports the study of the mechanism of extraction of americium from acid aqueous solutions by using the diethyl-2hexyl-pyro-phosphoric acid. Several aspects are thus discussed: influence of concentration of H 2 DEHPP, influence of the acidity of the aqueous phase, saturation of extracting agent, influence of the diluting agent, complexing of americium, influence of other cations. In a second part, the author reports the application to the recovery of americium from effluents, and discusses the obtained results

Environmental impact of a teratogenic actinide: a case study of americium-241

Energy Technology Data Exchange (ETDEWEB)

Wang, J.; Yang, J.Y.

1985-10-16

Americium-241 is widely used as a radiation source, but it also has some potential risk if taken into the body. Although the radiotoxicity of americium-241 is small compared to other transuranic actinides, its effects on the reproductive system and on development of the placenta are more damaging than the effects of plutonium-239. A previous report based on a worst-case scenario involving a hypothetical fire accident in a contaminated facility indicated that there could have been a significant impact on nearby residents from a unit release of americium-241 via atmospheric dispersion. However, because the facility is located in a rural region where most drinking water supplies are drawn from private wells, it is believed that deposition of americium-241 from the atmosphere might also have impacts via the groundwater pathway by infiltration of rainwater. In this analysis, a three-dimensional analytical mathematical model is used to assess several aspects of americium-241 contamination of groundwater, including radioactive transformation, advection, dispersion, and soil sorption. Simulation results indicate that no significant radiological impacts would occur to the nearby residents via the groundwater pathway. 15 refs., 2 figs., 2 tabs.

Environmental impact of a teratogenic actinide: a case study of americium-241

International Nuclear Information System (INIS)

Wang, J.; Yang, J.Y.

1985-01-01

Americium-241 is widely used as a radiation source, but it also has some potential risk if taken into the body. Although the radiotoxicity of americium-241 is small compared to other transuranic actinides, its effects on the reproductive system and on development of the placenta are more damaging than the effects of plutonium-239. A previous report based on a worst-case scenario involving a hypothetical fire accident in a contaminated facility indicated that there could have been a significant impact on nearby residents from a unit release of americium-241 via atmospheric dispersion. However, because the facility is located in a rural region where most drinking water supplies are drawn from private wells, it is believed that deposition of americium-241 from the atmosphere might also have impacts via the groundwater pathway by infiltration of rainwater. In this analysis, a three-dimensional analytical mathematical model is used to assess several aspects of americium-241 contamination of groundwater, including radioactive transformation, advection, dispersion, and soil sorption. Simulation results indicate that no significant radiological impacts would occur to the nearby residents via the groundwater pathway. 15 refs., 2 figs., 2 tabs

Modelling of curium and americium behaviour during separation with displacing complexing chromatography

International Nuclear Information System (INIS)

Chuveleva, Eh.A.; Kharitonov, O.V.; Firsova, L.A.

1994-01-01

Certain heavy rare earths, curium and americium were separated by the method of displacement complexing chromatography using DTPA solutions and solutions containing DTPA and citric acid as eluents. Separation factors of rare earths and curium (americium) were calculated. Imitators for curium and americium separation were suggested: thulium for curium elution using 0.025 mol/l DTPA, holmium-for curium elution using 0.025 mol/l DTPA in the presence of 0.025 mol/l citric acid; terbium can serve as the imitator in both cases. 5 refs., 5 figs

Barium iodide and strontium iodide crystals andd scintillators implementing the same

Science.gov (United States)

Payne, Stephen A; Cherepy, Nerine J; Hull, Giulia E; Drobshoff, Alexander D; Burger, Arnold

2013-11-12

In one embodiment, a material comprises a crystal comprising strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector according to another embodiment includes a scintillator optic comprising europium-doped strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector in yet another embodiment includes a scintillator optic comprising SrI.sub.2 and BaI.sub.2, wherein a ratio of SrI.sub.2 to BaI.sub.2 is in a range of between 0:1 A method for manufacturing a crystal suitable for use in a scintillator includes mixing strontium iodide-containing crystals with a source of Eu.sup.2+, heating the mixture above a melting point of the strontium iodide-containing crystals, and cooling the heated mixture near the seed crystal for growing a crystal. Additional materials, systems, and methods are presented.

Rare earth elements during diagenesis of abyssal sediments: analogies with a transuranic element americium

International Nuclear Information System (INIS)

Boust, D.

1987-03-01

One of the possibilities for the storage of high-level radioactive wastes consists in burying them into abyssal sediments, the sediments being supposed to barrier out radionuclides migration. The objective of the work was to estimate the efficiency of sediment barrier with respect to americium. As there is no americium in abyssal sediments, an indirect approach was used: the behaviour of the rare earth elements, the best natural analogs of americium. They were analysed in a 15 m long core, from the Cap Verde abyssal plateau. The terrigenous phase derived from the African continent was modified by short-term processes (1-1000 years); the intermediate rare earth elements were dissolved. Mineral coatings, enriched in rare earth appeared. After burial, the evolution continued at a much slower rate (10 5 - 10 6 years). The rare elements of the mineral coatings derived from the dissolution of the terrigenous phase and from an additional source, deeper in the sediment column. The fluxes of rare earth elements from sediment to water column were estimated. In suboxic sediments, the dissolved particulate equilibrium was related to redox conditions. The short-term reactivity of americium was studied in laboratory experiments. Simple americium migration models showed that the sediments barrier was totally efficient with respect to americium. In the conditions, neptunium 237 a daughter product of americium 241 could induce fluxes of 10 16 atoms per year per ton of stored waste (10 -8 Ci y-1), during millions years, towards the water column [fr

Biochemical fractionation and cellular distribution of americium and plutonium in the biomass of freshwater macrophytes

International Nuclear Information System (INIS)

Zotina, T.A.; Kalacheva, G.S.; Bolsunovsky, A.Ya.

2011-01-01

Accumulation of americium ( 241 Am) and plutonium ( 238,242 Pu) and their distribution in cell compartments and biochemical components of the biomass of freshwater aquatic plants Elodea canadensis, Ceratophyllum demersum and Myrioplyllum spicatum and aquatic moss Fontinalis antipyretica have been investigated in laboratory experiments. Americium and plutonium taken up from water by Elodea canadensis apical shoots were mainly absorbed by structural components of plant cells (90% for 241 Am; 89% for 238 Pu and 82-87% for 242 Pu). About 10-18% of isotope activity was recorded in the cytosol fraction. The major concentration (76-92%) of americium was bound to cell wall cellulose-like polysaccharides of Elodea canadensis, Myriophyllum spicatum, Ceratophyllum demersum and Fontinalis antipyretica, 8-24% of americium activity was registered in the fraction of proteins and carbohydrates, and just a minor concentration (<1%) in the lipid fraction. The distribution of plutonium in the biomass fractions of Elodea was similar to that of americium. Hence, americium and plutonium had the highest affinity to cellulose-like polysaccharides of cell walls of freshwater submerged macrophytes. (author)

Pyrochemical investigations into recovering plutonium from americium extraction salt residues

International Nuclear Information System (INIS)

Fife, K.W.; West, M.H.

1987-05-01

Progress into developing a pyrochemical technique for separating and recovering plutonium from spent americium extraction waste salts has concentrated on selective chemical reduction with lanthanum metal and calcium metal and on the solvent extraction of americium with calcium metal. Both techniques are effective for recovering plutonium from the waste salt, although neither appears suitable as a separation technique for recycling a plutonium stream back to mainline purification processes. 17 refs., 13 figs., 2 tabs

Supercritical Fluid Extraction of Plutonium and Americium from Soil

International Nuclear Information System (INIS)

Fox, R.V.; Mincher, B.J.

2002-01-01

Supercritical fluid extraction (SFE) of plutonium and americium from soil was successfully demonstrated using supercritical fluid carbon dioxide solvent augmented with organophosphorus and beta-diketone complexants. Spiked Idaho soils were chemically and radiologically characterized, then extracted with supercritical fluid carbon dioxide at 2,900 psi and 65 C containing varying concentrations of tributyl phosphate (TBP) and thenoyltrifluoroacetone (TTA). A single 45 minute SFE with 2.7 mol% TBP and 3.2 mol% TTA provided as much as 88% ± 6.0 extraction of americium and 69% ± 5.0 extraction of plutonium. Use of 5.3 mol% TBP with 6.8 mol% of the more acidic beta-diketone hexafluoroacetylacetone (HFA) provided 95% ± 3.0 extraction of americium and 83% ± 5.0 extraction of plutonium in a single 45 minute SFE at 3,750 psi and 95 C. Sequential chemical extraction techniques were used to chemically characterize soil partitioning of plutonium and americium in pre-SFE soil samples. Sequential chemical extraction techniques demonstrated that spiked plutonium resides primarily (76.6%) in the sesquioxide fraction with minor amounts being absorbed by the oxidizable fraction (10.6%) and residual fractions (12.8%). Post-SFE soils subjected to sequential chemical extraction characterization demonstrated that 97% of the oxidizable, 78% of the sesquioxide and 80% of the residual plutonium could be removed using SFE. These preliminary results show that SFE may be an effective solvent extraction technique for removal of actinide contaminants from soil

Gut uptake factors for plutonium, americium and curium

International Nuclear Information System (INIS)

Harrison, J.D.

1982-01-01

Data on estimates of the absorption of plutonium, americium and curium from the human gut based on measurements of uptake in other mammalian species are reviewed. It is proposed that for all adult members of the public ingesting low concentrations of plutonium in food and water, 0.05% would be an appropriate value of absorption except when the conditions of exposure are known and a lower value can be justified. For dietary intakes of americium and curium, the available data do not warrant a change from the ICRP value of 0.05%. For newborn children ingesting americium, curium and soluble forms of plutonium, a value of 1% absorption is proposed for the first 3 months of life during which the infant is maintained on a milk diet. It is proposed that a value of 0.5% should be used for the first year of life to take account of the gradual maturation of the gut. In considering the ingestion of insoluble oxides of plutonium by infants, it is proposed that absorption is taken as 0.1% for the first 3 months and 0.05% for the first year. (author)

Uptake of americium-241 by algae and bacteria

Energy Technology Data Exchange (ETDEWEB)

Giesy, Jr, J P; Paine, D [Savannah River Ecology Lab., Aiken, S.C. (USA)

1978-01-01

The uptake of americium by three algae, Scenedesmus obliguus, Selenastrum capricomutum and Chlorella pyrenosdosa and a bacterium Aeromonas hydrophila was studied. Live and fixed cells of each algal species and live bacterial cells were used. It is shown that algae and bacteria concentrate americium 241 to a high degree which makes them important links in the biomagnification phenomenon which may ultimately lead to a human hazard and be potentially important in recycling Am /sup 241/ in the water column and mobilization from sediments. Chemical fixation of algal cells caused increased uptake which indicated that uptake is by passive diffusion and probably due to chemical alteration of surface binding sites.

Iodide transport and breast cancer.

Science.gov (United States)

Poole, Vikki L; McCabe, Christopher J

2015-10-01

Breast cancer is the second most common cancer worldwide and the leading cause of cancer death in women, with incidence rates that continue to rise. The heterogeneity of the disease makes breast cancer exceptionally difficult to treat, particularly for those patients with triple-negative disease. To address the therapeutic complexity of these tumours, new strategies for diagnosis and treatment are urgently required. The ability of lactating and malignant breast cells to uptake and transport iodide has led to the hypothesis that radioiodide therapy could be a potentially viable treatment for many breast cancer patients. Understanding how iodide is transported, and the factors regulating the expression and function of the proteins responsible for iodide transport, is critical for translating this hypothesis into reality. This review covers the three known iodide transporters - the sodium iodide symporter, pendrin and the sodium-coupled monocarboxylate transporter - and their role in iodide transport in breast cells, along with efforts to manipulate them to increase the potential for radioiodide therapy as a treatment for breast cancer. © 2015 Society for Endocrinology.

Complex crystals formed in the aqueous solution of copper(I) iodide and sodium iodide

International Nuclear Information System (INIS)

Sugasaka, Kazuhiko; Fujii, Ayako

1977-01-01

Crystals of different crystal habits were separated from the copper(I) iodide and sodium iodide solution and the thermal changes of the composition of copper(I) iodide and sodium iodide complexes were studied by chemical analysis, thermal analysis and X-ray diffractometry. Granular and columnar crystals were determined to be copper(I) iodide and sodium iodide dihydrate by X-ray diffraction analysis, respectively. Needle crystal (A) which was separated from the solution at 25 0 C was assumed to be Na 2 CuI 3 .6H 2 O. (A) was stable in its appearance in the air, but the X-ray diffraction pattern of (A) changed. Needle crystal (B) which was recrystallized at 10 0 C from mother liquor after the separation of crystal (A) was assumed to be NaCuI 2 .4H 2 O. (B) was hygroscopic and decomposed to precipitate copper(I) iodide with moisture in the air. (A) and (B) were found to change by heating and or drying, respectively, as follows: Na 2 CuI 3 .6H 2 O → (-2H 2 O, 80 0 C) → 2NaI.2H 2 O + CuI → (-4H 2 O, 160 0 C) → 2NaI + CuI → (+1/2O 2 , 450 0 C) → 2NaI + CuO + 1/2I 2 , NaCuI 2 .4H 2 O → (-4H 2 O, Dried) → NaI + CuI. (auth.)

Synergistic extraction behaviour of americium from simulated acidic waste solutions

International Nuclear Information System (INIS)

Pathak, P.N.; Veeraraghavan, R.; Mohapatra, P.K.; Manchanda, V.K.

1998-01-01

The extraction behaviour of americium has been investigated with mixtures of 3-phenyl-4-benzoyl-5-isoxazolone (PBI) and oxodonors viz. tri-n-butyl phosphate (TBP), tri-n-octyl phosphine oxide (TOPO) and di-n-butyl octanamide (DBOA) using dodecane as the diluent from 1-6 M HNO 3 media. It is observed that D Am remains unaltered with PBI concentration (in the range 0.06-0.1 M) at 1.47 M TBP in the entire range of HNO 3 concentration. PBI and TBP in combination appears more promising compared to other synergistic systems. The possibility of using this mixture for americium removal from high level liquid waste solution has been explored. Extraction studies indicated that prior removal of uranium by 20% TBP in dodecane is helpful in the quantitative recovery of americium in three contacts. Effect of lanthanides on D Am is found to be marginal. (orig.)

Reduction Rates for Higher Americium Oxidation States in Nitric Acid

Energy Technology Data Exchange (ETDEWEB)

Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schmitt, Nicholas C [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-09-30

The stability of hexavalent americium was measured using multiple americium concentrations and nitric acid concentrations after contact with the strong oxidant sodium bismuthate. Contrary to our hypotheses Am(VI) was not reduced faster at higher americium concentrations, and the reduction was only zero-order at short time scales. Attempts to model the reduction kinetics using zero order kinetic models showed Am(VI) reduction in nitric acid is more complex than the autoreduction processes reported by others in perchloric acid. The classical zero-order reduction of Am(VI) was found here only for short times on the order of a few hours. We did show that the rate of Am(V) production was less than the rate of Am(VI) reduction, indicating that some Am(VI) undergoes two electron-reduction to Am(IV). We also monitored the Am(VI) reduction in contact with the organic diluent dodecane. A direct comparison of these results with those in the absence of the organic diluent showed the reduction rates for Am(VI) were not statistically different for both systems. Additional americium oxidations conducted in the presence of Ce(IV)/Ce(III) ions showed that Am(VI) is reduced without the typical growth of Am(V) observed in the systems sans Ce ion. This was an interesting result which suggests a potential new reduction/oxidation pathway for Am in the presence of Ce; however, these results were very preliminary, and will require additional experiments to understand the mechanism by which this occurs. Overall, these studies have shown that hexavalent americium is fundamentally stable enough in nitric acid to run a separations process. However, the complicated nature of the reduction pathways based on the system components is far from being rigorously understood.

Americium Separations from High-Salt Solutions Using Anion Exchange

International Nuclear Information System (INIS)

Barr, Mary E.; Jarvinen, Gordon D.; Stark, Peter C.; Chamberlin, Rebecca M.; Bartsch, Richard A.; Zhang, Z.Y.; Zhao, W.

2001-01-01

The aging of the US nuclear stockpile presents a number of challenges, including the increasing radioactivity of plutonium residues due to the ingrowth of 241 Am from the β-decay of 241 Pu. We investigated parameters that affect the sorption of Am onto anion-exchange resins from concentrated effluents derived from nitric acid processing of plutonium residues. These postevaporator wastes are nearly saturated solutions of acidic nitrate salts, and americium removal is complicated by physical factors, such as solution viscosity and particulates, as well as by the presence of large quantities of competing metals and acid. Single- and double-contact batch distribution coefficients for americium and neodymium from simple and complex surrogate solutions are presented. Varied parameters include the nitrate salt concentration and composition and the nitric acid concentration. We find that under these extremely concentrated conditions, Am(III) removal efficiencies can surpass 50% per contact. Distribution coefficients for both neodymium and americium are insensitive to solution acidity and appear to be driven primarily by low water activities of the solutions

Organic components and plutonium and americium state in soils and soil solutions

International Nuclear Information System (INIS)

Sokolik, G.A.; Ovsyannikova, S.V.; Kimlenko, I.M.

2002-01-01

The fraction composition of humus substances of different type soils and soil solutions have been studied. A distribution of Pu 239, 240 and Am 241 between humus substances fractions of different dispersity and mobility in soil-vegetation cover has been established. It was shown that humus of organic soils fixes plutonium and americium in soil medium in greater extent than humus of mineral soils. That leads to lower migration ability of radionuclides in organic soils. The lower ability of americium to form difficultly soluble organic and organic-mineral complexes and predomination of its anion complexes in soil solutions may be a reason of higher mobility and biological availability of americium in comparison to plutonium during soil-plant transfer (authors)

In-line measurement of plutonium and americium in mixed solutions

International Nuclear Information System (INIS)

Li, T.K.

1981-01-01

A solution assay instrument (SAI) has been developed at the Los Alamos National Laboratory and installed in the plutonium purification and americium recovery process area in the Los Alamos Plutonium Processing Facility. The instrument is designed for accurate, timely, and simultaneous nondestructive analysis of plutonium and americium in process solutions that have a wide range of concentrations and Am/Pu ratios. For a 25-mL sample, the assay precision is 5 g/L within a 2000-s count time

Production of Molecular Iodine and Tri-iodide in the Frozen Solution of Iodide: Implication for Polar Atmosphere.

Science.gov (United States)

Kim, Kitae; Yabushita, Akihiro; Okumura, Masanori; Saiz-Lopez, Alfonso; Cuevas, Carlos A; Blaszczak-Boxe, Christopher S; Min, Dae Wi; Yoon, Ho-Il; Choi, Wonyong

2016-02-02

The chemistry of reactive halogens in the polar atmosphere plays important roles in ozone and mercury depletion events, oxidizing capacity, and dimethylsulfide oxidation to form cloud-condensation nuclei. Among halogen species, the sources and emission mechanisms of inorganic iodine compounds in the polar boundary layer remain unknown. Here, we demonstrate that the production of tri-iodide (I3(-)) via iodide oxidation, which is negligible in aqueous solution, is significantly accelerated in frozen solution, both in the presence and the absence of solar irradiation. Field experiments carried out in the Antarctic region (King George Island, 62°13'S, 58°47'W) also showed that the generation of tri-iodide via solar photo-oxidation was enhanced when iodide was added to various ice media. The emission of gaseous I2 from the irradiated frozen solution of iodide to the gas phase was detected by using cavity ring-down spectroscopy, which was observed both in the frozen state at 253 K and after thawing the ice at 298 K. The accelerated (photo-)oxidation of iodide and the subsequent formation of tri-iodide and I2 in ice appear to be related with the freeze concentration of iodide and dissolved O2 trapped in the ice crystal grain boundaries. We propose that an accelerated abiotic transformation of iodide to gaseous I2 in ice media provides a previously unrecognized formation pathway of active iodine species in the polar atmosphere.

Americium/Curium Disposition Life Cycle Planning Study

International Nuclear Information System (INIS)

Jackson, W.N.; Krupa, J.; Stutts, P.; Nester, S.; Raimesch, R.

1998-01-01

At the request of the Department of Energy Savannah River Office (DOE- SR), Westinghouse Savannah River Company (WSRC) evaluated concepts to complete disposition of Americium and Curium (Am/Cm) bearing materials currently located at the Savannah River Site (SRS)

Iodide uptake by negatively charged clay interlayers?

International Nuclear Information System (INIS)

Miller, Andrew; Kruichak, Jessica; Mills, Melissa; Wang, Yifeng

2015-01-01

Understanding iodide interactions with clay minerals is critical to quantifying risk associated with nuclear waste disposal. Current thought assumes that iodide does not interact directly with clay minerals due to electrical repulsion between the iodide and the negatively charged clay layers. However, a growing body of work indicates a weak interaction between iodide and clays. The goal of this contribution is to report a conceptual model for iodide interaction with clays by considering clay mineral structures and emergent behaviors of chemical species in confined spaces. To approach the problem, a suite of clay minerals was used with varying degrees of isomorphic substitution, chemical composition, and mineral structure. Iodide uptake experiments were completed with each of these minerals in a range of swamping electrolyte identities (NaCl, NaBr, KCl) and concentrations. Iodide uptake behaviors form distinct trends with cation exchange capacity and mineral structure. These trends change substantially with electrolyte composition and concentration, but do not appear to be affected by solution pH. The experimental results suggest that iodide may directly interact with clays by forming ion-pairs (e.g., NaI (aq) ) which may concentrate within the interlayer space as well as the thin areas surrounding the clay particle where water behavior is more structured relative to bulk water. Ion pairing and iodide concentration in these zones is probably driven by the reduced dielectric constant of water in confined space and by the relatively high polarizability of the iodide species. - Highlights: • Iodide sorption experiments were completed with a diverse array of clay minerals. • Iodide uptake trended with CEC and swamping electrolyte identity and concentration. • Results can be explained by considering the formation of ion pairs in clay interlayers

Selective leaching studies of deep-sea sediments loaded with americium, neptunium and plutonium

International Nuclear Information System (INIS)

Cole, T.G.; Higgo, J.J.W.; Cronan, D.S.; Rees, L.V.C.

1984-07-01

A series of selective leaching experiments were undertaken to investigate the solid phase speciation and distribution of americium, neptunium and plutonium which had been experimentally loaded onto different marine sediment types. The chemical leaches employed showed rather poor selectivity but certain trends were evident. Adsorption was not by ion exchange. Americium showed a preferential affinity for carbonate and plutonium for organic matter. Neptunium appeared to have no preferential affinities. Americium was sorbed by acetic acid residues (CaCO 3 removed) and by unleached carbonate-rich sediments with equal efficiency. This indicates that it is able to diversify its solid phase affinity/distribution depending upon which solid phases are available. (author)

On the role of different biocomponents of bile and excretions in the elimination of plutonium and americium from the body

International Nuclear Information System (INIS)

Shvydko, N.S.

1986-01-01

A study was made of the role of biocomponents of bile, urine and feces in the elimination of plutonium and americium from the organism. Plutonium 239 and americium 241 were separated in bile due to higher tropism of plutonium to low molecular weight addends, and of americium, to a protein-containing fraction. The status of plutonium excreted in feces was the same as the physicochemical status of americium. Plutonium 239 and americium 241 eliminated in urine were in a completely ultrafiltered state

Mobility of plutonium and americium through a shallow aquifer in a semiarid region

International Nuclear Information System (INIS)

Penrose, W.R.; Polzer, W.L.; Essington, E.H.; Nelson, D.M.; Orlandini, K.A.

1990-01-01

Treated liquid wastes containing traces of plutonium and americium are released into Mortandad Canyon, within the site of Los Alamos National Laboratory, NM. The wastes infiltrate a small aquifer within the canyon. Although laboratory studies have predicted that the movement of actinides in subsurface environments will be limited to less than a few meters, both plutonium and americium are detectable in monitoring wells as far as 3,390 m downgradient from the discharge. Between the first and last monitoring wells (1.8 and 3.4 km from the discharge), plutonium concentrations decreased exponentially from 1,400 to 0.55 mBq/L. Americium concentrations ranged between 94 and 1,240 mBq/L, but did not appear to vary in a systematic way with distance. Investigation of the properties of the mobile actinides indicates that the plutonium and part of the americium are tightly or irreversibly associated with colloidal material between 25 and 450 nm in size. The colloidally bound actinides are removed only gradually from the groundwater. The fraction of the americium not associated with colloids exists in a low molecular weight form (diameter, ≤ 2 nm) and appears to be a stable, anionic complex of unknown composition. The mobile forms of these actinides defeat the forces that normally act to retard their movement through groundwater systems

Americium-241 and -243 as an ion-engine propellant

International Nuclear Information System (INIS)

Schachter, M.M.

1994-01-01

Commercially available americium-241 and -243 can be obtained as the mixture of the two isotopes in 100-gram quantities--a product of reprocessing spent nuclear powerplant fuel elements along with plutonium. The half-lives of the isotopes are 450 years for the -241 and 8,000 years for the -243 (the plutonium half-life isotope so obtained is 24,000 years). Americium rolled out in thin foil sheets emits alpha-rays (helium-4 ions) and beta-rays--2 valence electrons for each helium ion. Electrons are also considered as ions. As a foil, the americium radiates only a minimal amount of gamma-rays via the Curie effect. With appropriately designed permanent magnet rings insulated with Wood's alloy, the + and - ions can be accelerated from their already 5.5 million electron-Volts to billion and even trillions of electron-Volts by electronic control grids powered by the magnetohydrodynamic effect of electrons and helium ions streaming at the post-rocket nozzle of the ion engine. Protocol for the estimated thrust of this ion rocket engine is more than ten kilograms continuously sustainable for several thousand years

The ingestion of plutonium and americium by range cattle

International Nuclear Information System (INIS)

Blincoe, C.; Bohman, V.R.; Smith, D.D.

1981-01-01

The intake of plutonium and americium in the diet of cattle grazing on plutonium contaminated desert range was determined. Daily feed intake of the grazing animals was also determined so that the amount of nuclides ingested daily could be ascertained. Soil ingested by range cattle constituted the principal and possibly only source of ingested plutonium and americium and resulted in a daily intake of 3600-6600 pCi 238 Pu, 85,000-400,000 pCi 239 Pu, and 11,000-31,000 pCi 241 Am daily. Determining transuranic intake by direct measurement and from the composition and contamination of the diet gave identical results. (author)

Iodide uptake by negatively charged clay interlayers?

Science.gov (United States)

Miller, Andrew; Kruichak, Jessica; Mills, Melissa; Wang, Yifeng

2015-09-01

Understanding iodide interactions with clay minerals is critical to quantifying risk associated with nuclear waste disposal. Current thought assumes that iodide does not interact directly with clay minerals due to electrical repulsion between the iodide and the negatively charged clay layers. However, a growing body of work indicates a weak interaction between iodide and clays. The goal of this contribution is to report a conceptual model for iodide interaction with clays by considering clay mineral structures and emergent behaviors of chemical species in confined spaces. To approach the problem, a suite of clay minerals was used with varying degrees of isomorphic substitution, chemical composition, and mineral structure. Iodide uptake experiments were completed with each of these minerals in a range of swamping electrolyte identities (NaCl, NaBr, KCl) and concentrations. Iodide uptake behaviors form distinct trends with cation exchange capacity and mineral structure. These trends change substantially with electrolyte composition and concentration, but do not appear to be affected by solution pH. The experimental results suggest that iodide may directly interact with clays by forming ion-pairs (e.g., NaI(aq)) which may concentrate within the interlayer space as well as the thin areas surrounding the clay particle where water behavior is more structured relative to bulk water. Ion pairing and iodide concentration in these zones is probably driven by the reduced dielectric constant of water in confined space and by the relatively high polarizability of the iodide species. Copyright © 2015 Elsevier Ltd. All rights reserved.

The availability of plutonium and americium in Irish Sea sediments for re-dissolution

International Nuclear Information System (INIS)

McDonald, P.; Vives i Batlle, J.; Bousher, A.; Whittall, A.; Chambers, N.

2001-01-01

The availability of plutonium and americium, for re-dissolution from offshore sediments into Irish Sea water, has been examined. Sediments collected from the mud-patch near the Cumbrian coast were characterized in terms of spatial location, particle size, partitioning of radionuclides with respect to physico-chemical bonds and availability of actinides for release into seawater. Sequential extraction investigations revealed that plutonium was predominantly associated with strongly bound sesquioxide and organic complex fractions. Americium was associated mainly with the organic complex fraction, but a significant fraction was in carbonate form. Sediment/water re-dissolution experiments with and without stirring were compared to simulate the effect of disturbing bed sediment. After 1 week, neither set of re-dissolution data provided significant trends between dissolved activity and time. Stirred systems appeared to release 2.5 times more plutonium and americium into seawater than unstirred systems. Measured 239,240Pu and 241Am distribution coefficients (K d values) were both typically approximately 10 5 l kg -1 . 241Am K d values are an order of magnitude lower than previously reported for the north-eastern Irish Sea, but similar to western Irish Sea values. Overall, the fractions of plutonium and americium available for re-dissolution from bed sediment are very low at <0.1%, with proportionally more plutonium being released than americium. These findings lend further support for the extrapolation of laboratory-derived information to environmental conditions

Biokinetic study of plutonium and americium associated to the particulates of soil

International Nuclear Information System (INIS)

Espinosa, A.; Aragon, A.; Martinez, J.; Iranzo, C.E.

1996-01-01

The object of this study is to determine the biokinetic parameters of different Plutonium isotopes and Americium inhaled in the state in which they are found in the environment as a result of their deposition in the soil, from an aviation accident that generated different plutonium oxides. to achieve this objective, two lines of work planned. One was the determination of the mineralogical composition and associations that plutonium and americium present in that soil 22 years after the nuclear accident. Other studies were directed to determine the biokinetic of the plutonium isotopes and americium (contained in the dust) deposited tracheally and inhaled by laboratory animals (rats) and in vitro experiments by pulmonary leaching simulation. The in vivo tests have been developed in NRPB (U.K.) and the in vitro experiment, geochemical associations studies, assessment of internal doses to humans resulting from intake of plutonium and americium bearing dusts present in the contaminated area and establishment of ALIs for inhalation, were carried out in CIEMAT (Spain). In this work only determinations and experiments carried out by CIEMAT are includes as a part of the EU Project ''INHALATION AND INGESTION OF RADIONUCLIDES'' contract: FI3P-CT920064a. (Author) 10 refs

Determination of specific activity of americium and plutonium in selected environmental samples

International Nuclear Information System (INIS)

Trebunova, T.

1999-01-01

The aim of this work was development of method for determination of americium and plutonium in environmental samples. Developed method was evaluated on soil samples and after they was applied on selected samples of fishes (smoked mackerel, herring and fillet from Alaska hake). The method for separation of americium is based on liquid separation with Aliquate-336, precipitation with oxalic acid and using of chromatographic material TRU-Spec TM .The intervals of radiochemical yields were from 13.0% to 80.9% for plutonium-236 and from 10.5% to 100% for americium-241. Determined specific activities of plutonium-239,240 were from (2.3 ± 1.4) mBq/kg to (82 ± 29) mBq/kg, the specific activities of plutonium-238 were from (14.2 ± 3.7) mBq/kg to (708 ± 86) mBq/kg. The specific activities of americium-241 were from (1.4 ± 0.9) mBq/kg to (3360 ± 210) mBq/kg. The fishes from Baltic Sea as well as from North Sea show highest specific activities then fresh-water fishes from Slovakia. Therefore the monitoring of alpha radionuclides in foods imported from territories with nuclear testing is recommended

1976 Hanford americium exposure incident: psychological aspects

International Nuclear Information System (INIS)

Brown, W.R.

1982-01-01

Accidents involving exposure to radiation or radioactive materials may involve an unusual degree of emotional trauma. Methods that may be employed in dealing with such trauma are discussed in relation to a specific accident in which a radiation worker was injured and seriously contaminated with americium-241

Influence of organic components on plutonium and americium speciation in soils and soil solutions

International Nuclear Information System (INIS)

Sokolik, G.A.; Ovsyannikova, S.V.; Kimlenko, I.M.

2003-01-01

Group composition of humic substances of organic and mineral soils sampled in the 30-km zone of the Chernobyl accident was analyzed for studying influence of organic components on migration properties of plutonium and americium in soils and soil solutions by the method of gel-chromatography and chemical fractionation. It was ascertained that humus of organic soils binds plutonium and americium stronger than humus of mineral soils. Elevated mobility of americium compared to plutonium one stems from lower ability of the latter to from hard to solve organic and organomineral complexes, as well as from its ability to form anionic complexes in soil solutions [ru

Electrochemical reaction rates in a dye-sensitised solar cell - the iodide/tri-iodide redox system

DEFF Research Database (Denmark)

Bay, L.; West, K.; Winther-Jensen, B.

2006-01-01

The electrochemical reaction rate of the redox couple iodide/tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide....../tri-iodide couple should be fast at the counter electrode, i.e. this electrode must have a high catalytic activity towards the redox couple, and the same reaction must be slow on the photo electrode. The catalytic activity is investigated for platinum, poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy......), and polyaniline (PANI)-all deposited onto fluorine-doped tin oxide (FTO) glass. Both Pt and PEDOT are found to have sufficiently high catalytic activities for practical use as counter electrodes in DSSC. The reaction resistance on FTO and anatase confirmed the beneficial effect of a compact anatase layer on top...

Electrochemical reaction rates in a dye sentisised solar cell - the iodide/tri-iodide redox system

DEFF Research Database (Denmark)

Bay, Lasse; West, Keld; Winter-Jensen, Bjørn

2006-01-01

The electrochemical reaction rate of the redox couple iodide / tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide / tri......-iodide couple should be fast at the counter electrode, i.e. this electrode must have a high catalytic activity towards the redox couple, and the same reaction must be slow on the photo electrode. The catalytic activity is investigated for platinum, poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy......), and polyaniline (PANI) - all deposited onto fluorine doped tin oxide (FTO) glass. Both Pt and PEDOT are found to have sufficiently high catalytic activities for practical use as counter electrode in DSSC. The reaction resistance on FTO and anatase confirmed the beneficial effect of a compact anatase layer on top...

Carbamoyl methylphosphine oxide derivatives of adamantane as americium and europium extractants

International Nuclear Information System (INIS)

Babain, V.A.; Alyapyshev, M.Yu.; Novakov, I.A.; Orlinson, B.S.; Savel'ev, E.N.; Shokova, Eh.A.; Serebrayannikova, A.E.; Kovalev, V.V.

2007-01-01

Adamantane di-1,3-carbamoyl methylphosphine oxide (CMPO) derivatives, where CMPO-groups connect with 1,3-positions of rigid adamantane platform by methylene and ethylene bridges, are synthesized, and their efficiency as extractants of americium(III) and europium(III) from nitric acid solutions is demonstrated. Distribution function of Am 3+ and Eu + during extraction from 3M HNO 3 are measured in the investigation of extraction properties. It is noted that first synthesized adamantane CMPO derivatives are more effective for the extraction of americium(III) and europium(III) from 3MHNO 3 [ru

Radiation protection data sheets for the use of Americium 241 in unsealed sources

International Nuclear Information System (INIS)

Anon.

1993-01-01

This radiation protection data sheet is intended for supervisors and staff in the different medical, hospital, pharmaceutical, university and industrial laboratories and departments where Americium 241 is handled, and also for all those involved in risk prevention in this field. It provides essential data on radiation protection measures during the use of Americium 241 in unsealed sources: physical characteristics, risk assessment, administrative procedures, recommendations, regulations and bibliography

Adsorption-desorption characteristics of plutonium and americium with sediment particles in the estuarine environment: studies using plutonium-237 and americium-241

International Nuclear Information System (INIS)

Murray, C.N.; Fukai, R.

1975-01-01

The particle formation of plutonium and americium, their adsorption onto fresh water sediments and the desorption from the sediments in sea water were studied in the Laboratory under simulated river-estuary conditions, using γ-emitting plutonium-237 and americium-241. The results of the experiments show that the particle formation of plutonium depends on its valence states, on pH and on the salinity of the medium. For river water at pH4, some 25%, 20% and 30% of the added 237 Pu was in particulate form, larger than 0.45 μm, for Pu (III), Pu (IV) and Pu (VI), respectively, while 65%, 90% and 50% of the respective valence states was associated with particles at pH 8. In sea water the general pattern remains similar, although Pu (VI) is more soluble in sea water owing to higher ligand concentrations for carbonate and bicarbonate complexes. The pH-dependency of particle formation of Am (III) is more steep than that of plutonium and seems to be influenced by colloidal substances occurring in the experimental media. The adsorption-desorption characteristics of plutonium and americium with the sediment in river water as well as sea water reflect the characteristics of their particle formation, being dependent upon such properties as valence states, the pH and salinity of the medium. A sewage effluent added to the media has small but measurable effects on the adsorption-desorption processes of plutonium. (author)

Local Structure in Americium and Californium Hexa-cyanoferrates - Comparison with Their Lanthanide Analogues

International Nuclear Information System (INIS)

Dupouy, G.; Bonhoure, I.; Dumas, Th.; Moisy, Ph.; Petit, S.; Den Auwer, Ch.; Conradson, St.D.; Hennig, Ch.; Scheinost, A.C.; Le Naour, C.; Simoni, E.

2011-01-01

Metal hexa-cyanoferrates are well known molecular solids for a large variety of cations, although very little has been described for actinide adducts. Two new members of actinide(III) hexa-cyanoferrates were synthesized with the cations americium and californium. They were structurally characterized by infrared and X-ray absorption spectroscopy. Combined EXAFS data at the iron K edge and actinide L 3 edge provide evidence for a three-dimensional model for these two new compounds. Structural data in terms of bond lengths were compared to those reported for the parent lanthanide(III) compounds, neodymium and gadolinium hexa-cyanoferrates, respectively: the americium compound with (KNd(III)Fe(II)-Fe-III(CN) 6 .4H 2 O and the californium compound with (KGd(III)Fe(II)(CN) . 3.5H 2 O and (KGd(III)Fe(II)(CN) 6 .3H 2 O. This comparison between actinide and lanthanide homologues has been carried out on the basis of ionic radii considerations. The americium and neodymium environments appear to be very similar and are arranged in a tri-capped trigonal prism polyhedron of coordination number 9 (CN: 9), in which the americium atom is bonded to six nitrogen atoms and to three water molecules. For the californium adduct, a similar comparison and bond length and angle values derived from EXAFS studies suggest that the californium cation sits in a bi-capped trigonal prism (CN: 8) as in (KGd(III)Fe(II)(CN) 6 . 3H 2 O. This arrangement differs from that in the structure of (KGd(III)Fe(II)(CN) 6 .3.5H 2 O, in which the gadolinium atom is surrounded by 9 atoms. This is one of the rare pieces of information revealed by EXAFS spectroscopy for americium and californium in comparison to lanthanide atoms in molecular solid compounds. A discussion on the decrease in bond length and coordination number from americium to californium is also provided, on the basis of crystallographic results reported in the literature for actinide(III) and lanthanide(III) hydrate series. (authors)

Remobilization of americium in soil columns under experimental rhizo-spheric conditions

Energy Technology Data Exchange (ETDEWEB)

Perrier, T.; Martin-Garin, A.; Morello, M. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

2004-07-01

The biogeochemical behaviour of americium in subsurface soils plays a dominant role on the potential migration of this actinide, but is currently poorly known. The identification and understanding of these processes is of major concern for this highly (radio)toxic element and can allow the determination of its impact on the natural media. This research investigates the relevant processes controlling americium biogeochemical speciation in the rhizosphere of an agricultural soil. Lixiviation tests were performed on columns packed with a 2 mm-sieved calcareous soil contaminated with {sup 241}Am (500 Bq.g{sup -1}), under steady-state unsaturated or saturated hydric flow conditions. The columns were percolated with soil solution of varied compositions, containing citrate and/or glucose simulating root exudates in non-sterile conditions. The physico-chemical parameters of the outlet solution (pH, conductivity, major ions, organic acids) were monitored, as well as the microbial activity. Inorganic and organic speciation of {sup 241}Am is supported by geochemical modeling with JChess, using a thermodynamic database based on NEA database and the latest PSI recommendations. The percolation of a solution in equilibrium with the soil released small amount of americium (<5 mBq/cm{sup 3}), as predicted by the high {sup 241}Am K{sub d} values. 10{sup -4} M concentrations of citrate, glucose or both combined did not enhance remobilization either. Poor remobilization was also observed at high glucose concentrations (10{sup -2} M), despite an effective glucose microbial degradation, the production of ligands such as acetate, and important changes in the chemistry of the solution. On the contrary, high concentrations of citrate (10{sup -2} M) released 1000 times more americium, which is in accordance with previous studies. Even greater releases (10000 times) were observed when 10{sup -2} M glucose was added to 10{sup -2} M citrate. The remobilization of americium resulting from the

Enhanced iodide sequestration by 3-biphenyl-5,6-dihydroimidazo 2,1-b thiazole in sodium/iodide sym-porter (NIS)-expressing cells

International Nuclear Information System (INIS)

Lecat-Guillet, N.; Ambroise, Y.

2008-01-01

The ability of the sodium/iodide sym-porter (NIS) to take up iodide has long provided the basis for cyto-reductive gene therapy and cancer treatment with radio-iodide. One of the major limitations of this approach is that radio-iodide retention in NIS-expressing cells is not sufficient for their destruction. We identified and characterized a small organic molecule capable of increasing iodide retention in HEK293 cells permanently transfected with human NIS cDNA (hNIS-HEK293) and in the rat thyroid-derived cell line FRTL-5. In the presence of 3-biphenyl-4'-yl-5,6-dihydroimidazo[2,1-b)thiazole (ISA1), the transmembrane iodide concentration gradient was increased up to 4.5-fold. Our experiments indicate that the imidazo-thiazole derivative acts either by inhibiting anion efflux mechanisms, or by promoting the relocation of iodide into subcellular compartments. This new compound is not only an attractive chemical tool to investigate the mechanisms of iodide flux at the cellular level, but also opens promising perspectives in the treatment of cancer after NIS gene transfer. (authors)

1976 Hanford americium exposure incident: overview and perspective

International Nuclear Information System (INIS)

Thompson, R.C.

1982-01-01

Salient features of the 1976 Hanford americium exposure incident are discussed. Comparisons are made with previous human and animal exposure data, and conclusions drawn relative to the injured workman, to health physics practices, and to the adequacy of current exposure limits

Plutonium-239 and americium-241 uptake by plants from soil. Final report

International Nuclear Information System (INIS)

Brown, K.W.

1979-03-01

Alfalfa was grown in soil contaminated with plutonium-239 dioxide (239PuO2) at a concentration of 29.7 nanocuries per gram (nCi/g). In addition to alfalfa, radishes, wheat, rye, and tomatoes were grown in soils contaminated with americium-241 nitrate (241Am(NO3)3) at a concentration of 189 nCi/g. The length of exposure varied from 52 days for the radishes to 237 days for the alfalfa. The magnitude of plutonium incorporation by the alfalfa as indicated by the concentration ratio, 0.0000025, was similar to previously reported data using other chemical forms of plutonium. The results did indicate, however, that differences in the biological availability of plutonium isotopes do exist. All of the species exposed to americium-241 assimilated and translocated this radioisotope to the stem, leaf, and fruiting structures. The magnitude of incorporation as signified by the concentration ratios varied from 0.00001 for the wheat grass to 0.0152 for the radishes. An increase in the uptake of americium also occurred as a function of time for four of the five plant species. Evidence indicates that the predominant factor in plutonium and americium uptake by plants may involve the chelation of these elements in soils by the action of compounds such as citric acid and/or other similar chelating agents released from plant roots

Analysis for iodide in groundwater by x-ray fluorescence spectrometry after collection as silver iodide on activated charcoal

International Nuclear Information System (INIS)

Howe, P.T.

1980-01-01

The report describes the determination of microgram quantities of iodide in water by X-ray fluorescence spectrometry. The iodide is concentrated by precipitation as silver iodide on activated charcoal. If a 60-mL sample is available, a concentration of 0.12 mg/L can be detected. Precision (2σ) at the 1-mg/L level is +- 0.08 mg/L. (auth)

Methyl Iodide Decomposition at BWR Conditions

International Nuclear Information System (INIS)

Pop, Mike; Bell, Merl

2012-09-01

Based on favourable results from short-term testing of methanol addition to an operating BWR plant, AREVA has performed numerous studies in support of necessary Engineering and Plant Safety Evaluations prior to extended injection of methanol. The current paper presents data from a study intended to provide further understanding of the decomposition of methyl iodide as it affects the assessment of methyl iodide formation with the application of methanol at BWR Plants. This paper describes the results of the decomposition testing under UV-C light at laboratory conditions and its effect on the subject methyl iodide production evaluation. The study as to the formation and decomposition of methyl iodide as it is effected by methanol addition is one phase of a larger AREVA effort to provide a generic plant Safety Evaluation prior to long-term methanol injection to an operating BWR. Other testing phases have investigated the compatibility of methanol with fuel construction materials, plant structural materials, plant consumable materials (i.e. elastomers and coatings), and ion exchange resins. Methyl iodide is known to be very unstable, typically preserved with copper metal or other stabilizing materials when produced and stored. It is even more unstable when exposed to light, heat, radiation, and water. Additionally, it is known that methyl iodide will decompose radiolytically, and that this effect may be simulated using ultra-violet radiation (UV-C) [2]. In the tests described in this paper, the use of a UV-C light source provides activation energy for the formation of methyl iodide. Thus is similar to the effect expected from Cherenkov radiation present in a reactor core after shutdown. Based on the testing described in this paper, it is concluded that injection of methanol at concentrations below 2.5 ppm in BWR applications to mitigate IGSCC of internals is inconsequential to the accident conditions postulated in the FSAR as they are related to methyl iodide formation

Kinetics of americium(VI) mass transfer through solid supported liquid membrane with HDEHP

International Nuclear Information System (INIS)

Mikheeva, M.N.; Novicoov, P.; Myasoedov, B.F.; Tikhomirov, S.V.

1994-01-01

The main regularities of membrane extraction of americium under conditions of different redox potentials in aqueous phases have been studied. The physico-chemical model of the process including steps of americium oxidation in feed solution, extraction by membrane, partial reduction on membrane surface, trans-membrane diffusion and reextraction to strip solution has been developed. The calculation of reduction rate constant on membrane surface has been carried out. (author) 9 refs.; 4 figs.; 3 tabs

Kinetic Isotope Effects in the Reduction of Methyl Iodide

DEFF Research Database (Denmark)

Holm, Torkil

1999-01-01

a Grignard reagent to methyl iodide, and for reduction of methyl iodide with tributyltin hydride or with gaseous hydrogen iodide. Very small KIE's were found for electron transfer to methyl iodide from magnesium in ether or from sodium in ammonia. The reason may be that these reactions are transport...

On the structure of thorium and americium adenosine triphosphate complexes

International Nuclear Information System (INIS)

Mostapha, Sarah; Berton, Laurence; Boubals, Nathalie; Zorz, Nicole; Charbonnel, Marie-Christine; Fontaine-Vive, Fabien; Den Auwer, Christophe; Solari, Pier Lorenzo

2014-01-01

The actinides are chemical poisons and radiological hazards. One challenge to better appraise their toxicity and develop countermeasures in case of exposure of living organisms is to better assess pathways of contamination. Because of the high chemical affinity of those actinide elements for phosphate groups and the ubiquity of such chemical functions in biochemistry, nucleotides and in particular adenosine triphosphate nucleotide (ATP) may be considered critical target building blocks for actinides. Combinations of spectroscopic techniques (Fourier transformed Infra Red [FTIR], Electro-spray Ionization Mass Spectrometry [ESI-MS], and Extended X-ray Absorption Fine Structure [EXAFS]) with quantum chemical calculations have been implemented in order to assess the actinides coordination arrangement with ATP. We describe and compare herein the interaction of ATP with thorium and americium; thorium(IV) as a representative of actinide(IV) like plutonium(IV) and americium(III) as a representative of all heavier actinides. In the case of thorium, an insoluble complex is readily formed. In the case of americium, a behavior identical to that described previously for lutetium has been observed with insoluble and soluble complexes. The comparative study of ATP complexation with Th(IV) and Am(III) shows their ability to form insoluble complexes for which a structural model has been proposed by analogy with previously described Lu(III) complexes. (authors)

On the structure of thorium and americium adenosine triphosphate complexes.

Science.gov (United States)

Mostapha, Sarah; Fontaine-Vive, Fabien; Berthon, Laurence; Boubals, Nathalie; Zorz, Nicole; Solari, Pier Lorenzo; Charbonnel, Marie Christine; Den Auwer, Christophe

2014-11-01

The actinides are chemical poisons and radiological hazards. One challenge to better appraise their toxicity and develop countermeasures in case of exposure of living organisms is to better assess pathways of contamination. Because of the high chemical affinity of those actinide elements for phosphate groups and the ubiquity of such chemical functions in biochemistry, nucleotides and in particular adenosine triphosphate nucleotide (ATP) may be considered critical target building blocks for actinides. Combinations of spectroscopic techniques (Fourier transformed Infra Red [FTIR], Electrospray Ionization Mass Spectrometry [ESI-MS], and Extended X-ray Absorption Fine Structure [EXAFS]) with quantum chemical calculations have been implemented in order to assess the actinides coordination arrangement with ATP. We describe and compare herein the interaction of ATP with thorium and americium; thorium(IV) as a representative of actinide(IV) like plutonium(IV) and americium(III) as a representative of all heavier actinides. In the case of thorium, an insoluble complex is readily formed. In the case of americium, a behavior identical to that described previously for lutetium has been observed with insoluble and soluble complexes. The comparative study of ATP complexation with Th(IV) and Am(III) shows their ability to form insoluble complexes for which a structural model has been proposed by analogy with previously described Lu(III) complexes.

Airborne plutonium-239 and americium-241 concentrations measured from the 125-meter Hanford Meteorological Tower

International Nuclear Information System (INIS)

Sehmel, G.A.

1978-01-01

Airborne plutonium-239 and americium-241 concentrations and fluxes were measured at six heights from 1.9 to 122 m on the Hanford meteorological tower. The data show that plutonium-239 was transported on nonrespirable and small particles at all heights. Airborne americium-241 concentrations on small particles were maximum at the 91 m height

Environmental impacts of the release of a transuranic actinide, americium-241, from a contaminated facility

Energy Technology Data Exchange (ETDEWEB)

Want, J.; Merry-Libby, P.

1985-10-29

Americium-241 is widely used as a radiation source, but it also has some potential risk if taken into the body because of its high dose conversion factor. Although the radiotoxicity of americium-241 is small compared to other transuranic actinides, its effects on the reproductive system and on development of the placenta are more damaging than the effects of plutonium-239. In Ohio, a gemologist's laboratory was contaminated with americium-241. Prior to decontamination of the laboratory, potential radiological impacts to the surrounding environment were assessed. A hypothetical fire accident resulting in a unit release (1 curie) was assumed. Potential radiological impacts were simulated using an atmospheric dispersion and dosimetry model with local meteorological data, population census data, and detailed information regarding the neighborhood. The results indicate that there could have been a significant impact on nearby residents from americium-241 via atmospheric dispersion if a major catastrophic release had occurred prior to contamination and decommissioning of the laboratory. 14 refs., 3 figs., 2 tabs.

Airborne plutonium and americium concentrations measured from the top of Rattlesnake Mountain

International Nuclear Information System (INIS)

Sehmel, G.A.

1979-01-01

Airborne plutonium-239+240 and americium-241 blowing from offsite was measured in an initial experiment at the top of Rattlesnake Mountain. Average airborne concentration measured was similar to fallout concentrations. Airborne plutonium concentrations were independent of wind speed for seven wind speed increments between 0.5 and 31 m/sec. In contrast the airborne americium concentration was a minimum at a wind speed of approximately 7 m/sec. Similarly, the airborne solids concentration in μg/m 3 was a minimum at an intermediate wind speed increment of 7 to 11 m/sec

Americium-241 radioisotope thermoelectric generator development for space applications

International Nuclear Information System (INIS)

Ambrosi, Richard; Williams, Hugo; Samara-Ratna, Piyal

2013-01-01

Space nuclear power systems are under development in the UK in collaboration with European partners as part of a European Space Agency (ESA) programme. Radioisotope thermoelectric generators (RTG) are an important element of this new capability in Europe. RTG systems being developed in Europe are targeting the 10 W electric to 50 W electric power generation range adopting a modular scalable approach to the design. Radiogenic decay heat from radioisotopes can be converted to electrical power by using appropriate semiconductor based thermoelectric materials. The plan for Europe is to develop radioisotope space nuclear power systems based on both thermoelectric and Stirling power conversion systems. Although primarily focused on delivering up to 50 W of electrical power, the European radioisotope thermoelectric system development programme is targeting americium-241 as a fuel source and is maximizing the use of commercially available thermoelectric manufacturing processes in order to accelerate the development of power conversion systems. The use of americium provides an economic solution at high isotopic purity and is product of a separation process from stored plutonium produced during the reprocessing of civil nuclear fuel. A laboratory prototype that uses electrical heating as a substitute for the radioisotope was developed to validate the designs. This prototype has now been tested. This paper outlines the requirements for a European americium-241 fuelled RTG, describes the most recent updates in system design and provides further insight into recent laboratory prototype test campaigns. (author)

Americium-241 radioisotope thermoelectric generator development for space applications

Energy Technology Data Exchange (ETDEWEB)

Ambrosi, Richard; Williams, Hugo; Samara-Ratna, Piyal, E-mail: rma8@le.ac.uk [University of Leicester, (United Kingdom); and others

2013-07-01

Space nuclear power systems are under development in the UK in collaboration with European partners as part of a European Space Agency (ESA) programme. Radioisotope thermoelectric generators (RTG) are an important element of this new capability in Europe. RTG systems being developed in Europe are targeting the 10 W electric to 50 W electric power generation range adopting a modular scalable approach to the design. Radiogenic decay heat from radioisotopes can be converted to electrical power by using appropriate semiconductor based thermoelectric materials. The plan for Europe is to develop radioisotope space nuclear power systems based on both thermoelectric and Stirling power conversion systems. Although primarily focused on delivering up to 50 W of electrical power, the European radioisotope thermoelectric system development programme is targeting americium-241 as a fuel source and is maximizing the use of commercially available thermoelectric manufacturing processes in order to accelerate the development of power conversion systems. The use of americium provides an economic solution at high isotopic purity and is product of a separation process from stored plutonium produced during the reprocessing of civil nuclear fuel. A laboratory prototype that uses electrical heating as a substitute for the radioisotope was developed to validate the designs. This prototype has now been tested. This paper outlines the requirements for a European americium-241 fuelled RTG, describes the most recent updates in system design and provides further insight into recent laboratory prototype test campaigns. (author)

Uptake and effects of americium-241 on a brackish-water amphipod

Energy Technology Data Exchange (ETDEWEB)

Hoppenheit, M.; Murray, C.N.; Woodhead, D.S.

1980-01-01

The present paper reports the results of experimental work undertaken using the brackish-water amphipod Gammarus duebeni duebeni and the transuranium nuclide americium-241. Data on the accumulation of this actinide showed that the larger fraction of the total body burden is associated with the exoskeleton. It was found that the body burden remained constant in the range pH 8.0-6.5 even though the water concentration changed markedly. It would thus appear that the concept of a concentration factor should be re-examined and it is proposed that a factor should be defined in terms of environmental and chemical parameters which represent the bioavailable fraction of the actinide. The effect of americium on survival and moulting was studied at two activity concentrations; the dose rates and absorbed doses under the experimental conditions employed have been estimated. The differences in survival rates between the control and irradiated groups were statistically analyzed and the significant difference at the higher concentration is believed to be due to a synergism between physiological stress and radiotoxicity of americium rather than the chemical toxicity of the element.

Uptake and effects of americium-241 on a brackish-water amphipod

International Nuclear Information System (INIS)

Hoppenheit, M.; Murray, C.N.; Woodhead, D.S.

1980-01-01

The present paper reports the results of experimental work undertaken using the brackish-water amphipod Gammarus duebeni duebeni and the transuranium nuclide americium-241. Data on the accumulation of this actinide showed that the larger fraction of the total body burden is associated with the exoskeleton. It was found that the body burden remained constant in the range pH 8.0-6.5 even though the water concentration changed markedly. It would thus appear that the concept of a concentration factor should be re-examined and it is proposed that a factor should be defined in terms of environmental and chemical parameters which represent the bioavailable fraction of the actinide. The effect of americium on survival and moulting was studied at two activity concentrations; the dose rates and absorbed doses under the experimental conditions employed have been estimated. The differences in survival rates between the control and irradiated groups were statistically analyzed and the significant difference at the higher concentration is believed to be due to a synergism between physiological stress and radiotoxicity of americium rather than the chemical toxicity of the element. (orig.) [de

An experimental investigation of accumulation and transmutation behavior of americium in the MOX fuel irradiated in a fast reactor

International Nuclear Information System (INIS)

Osaka, Masahiko; Koyama, Shin-ichi; Maeda, Shigetaka; Mitsugashira, Toshiaki

2005-01-01

Americium isotopes generated in the MOX fuel irradiated in the experimental fast reactor JOYO were analyzed by applying a sophisticated radiochemical technique. Americium was isolated from the irradiated MOX fuel by a combined method of anion-exchange chromatography and oxidation of Am. The isotopic ratios of americium and its content were determined by thermal ionization mass spectroscopy and α-spectrometry, respectively. The americium isotopic ratio was similar for all the specimens, but was significantly different from that of PWR-MOX. On the basis of present analytical results, the accumulation and transmutation behavior of americium nuclides in a fast reactor is discussed from the viewpoints of neutron spectrum dependence and the isomeric ratio of the 241 Am capture reaction. The estimated isomeric ratio is about 87%, which is close to the latest evaluated value. A rapid estimation method of Am content by using the 240 Pu to 239 Pu ratio was adopted and proved to be valid for the spent fuel irradiated in the fast reactor

Iodide adsorption on the surface of chemically pretreated clinoptilolite

International Nuclear Information System (INIS)

Chmielewska-Horvatova, E.; Lesny, J.

1995-01-01

The possibility to use the monoionic Ag +- form (eventually Hg +- and Hg 2+ -forms) of clinoptilolite of domestic origin for radioactive iodide elimination from waters has been studied. The capacity of the monoforms of clinoptilolite towards iodide exceeds many times that of the capacity of clinoptilolite in natural form. Due to the low solubility product of AgI, Hg 2 I 2 and HgI 2 iodides generate precipitates on the zeolite surface. Rtg analyses of the silver form of clinoptilolite after sorption of iodide demonstrate the formation of new crystals on the zeolite surface. The influence of interfering anions on the adsorption capacity of silver clinoptilolite towards iodide was investigated, too. Kinetic curves of iodide desorption from the surface of silver and mercury clinoptilolite were compared. Simultaneously, adsorption isotherms for the systems aqueous iodide solution/Ag-, Hg-clinoptilolite were determined. (author) 6 refs.; 7 figs.; 4 tabs

Experimental studies to validate model calculations and maximum solubility limits for Plutonium and Americium; Experimentelle Arbeiten zur Absicherung von Modellrechnungen und Maximalkonzentrationen fuer Plutonium und Americium

Energy Technology Data Exchange (ETDEWEB)

NONE

2017-02-16

This report focuses on studies of KIT-INE to derive a significantly improved description of the chemical behaviour of Americium and Plutonium in saline NaCl, MgCl{sub 2} and CaCl{sub 2} brine systems. The studies are based on new experimental data and aim at deriving reliable Am and Pu solubility limits for the investigated systems as well as deriving comprehensive thermodynamic model descriptions. Both aspects are of high relevance in the context of potential source term estimations for Americium and Plutonium in aqueous brine systems and related scenarios. Americium and Plutonium are long-lived alpha emitting radionuclides which due to their high radiotoxicity need to be accounted for in a reliable and traceable way. The hydrolysis of trivalent actinides and the effect of highly alkaline pH conditions on the solubility of trivalent actinides in calcium chloride rich brine solutions were investigated and a thermodynamic model derived. The solubility of Plutonium in saline brine systems was studied under reducing and non-reducing conditions and is described within a new thermodynamic model. The influence of dissolved carbonate on Americium and Plutonium solubility in MgCl{sub 2} solutions was investigated and quantitative information on Am and Pu solubility limits in these systems derived. Thermodynamic constants and model parameter derived in this work are implemented in the Thermodynamic Reference Database THEREDA owned by BfS. According to the quality assurance approach in THEREDA, is was necessary to publish parts of this work in peer-reviewed scientific journals. The publications are focused on solubility experiments, spectroscopy of aquatic and solid species and thermodynamic data. (Neck et al., Pure Appl. Chem., Vol. 81, (2009), pp. 1555-1568., Altmaier et al., Radiochimica Acta, 97, (2009), pp. 187-192., Altmaier et al., Actinide Research Quarterly, No 2., (2011), pp. 29-32.).

21 CFR 172.375 - Potassium iodide.

Science.gov (United States)

2010-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be...

In Vitro Bioavailability Study of an Antiviral Compound Enisamium Iodide

OpenAIRE

Eleonore Haltner-Ukomadu; Svitlana Gureyeva; Oleksii Burmaka; Andriy Goy; Lutz Mueller; Grygorii Kostyuk; Victor Margitich

2018-01-01

An investigation into the biopharmaceutics classification and a study of the in vitro bioavailability (permeability and solubility) of the antiviral compound enisamium iodide (4-(benzylcarbamoyl)-1-methylpyridinium iodide) were carried out. The solubility of enisamium iodide was determined in four different buffers. Apparent intestinal permeability (Papp) of enisamium iodide was assessed using human colon carcinoma (Caco-2) cells at three concentrations. The solubility of enisamium iodide in ...

Molecular localisation of americium, technetium and cesium in edible marine animals. Their metabolic behavior and their consequences; Localisation moleculaire de l'americium, du technetium et du cesium chez des animaux marins comestibles leur comportement metabolique et ses consequences

Energy Technology Data Exchange (ETDEWEB)

Pieri, J; Goudard, F; Milcent, M C [Laboratoire de Biochimie et Radiochimie, Faculte des Sciences et des Techniques, Nantes Cedex (France)

1992-07-01

We show the molecular behavior of americium, technetium and cesium on the chromatographic pattern of each cytosol in the digestive gland of eel and lobster. The contamination by cadmium seems to compete with americium in the fractions of MW 10,000. Cesium shows an ionic behavior. (author)

Final Radiological Assessment of External Exposure for CLEAR-Line Americium Recovery Operations

Energy Technology Data Exchange (ETDEWEB)

Davis, Adam C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Belooussova, Olga N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hetrick, Lucas Duane [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2014-11-12

Los Alamos National Laboratory is currently planning to implement an americium recovery program. The americium, ordinarily isotopically pure 241Am, would be extracted from existing Pu materials, converted to an oxide and shipped to support fabrication of americium oxide-beryllium neutron sources. These operations would occur in the currently proposed Chloride Extraction and Actinide Recovery (CLEAR) line of glove boxes. This glove box line would be collocated with the currently-operational Experimental Chloride Extraction Line (EXCEL). The focus of this document is to provide an in-depth assessment of the currently planned radiation protection measures and to determine whether or not further design work is required to satisfy design-goal and ALARA requirements. Further, this document presents a history of americium recovery operations in the Department of Energy and high-level descriptions of the CLEAR line operations to provide a basis of comparison. Under the working assumptions adopted by this study, it was found that the evaluated design appears to mitigate doses to a level that satisfies the ALARA-in-design requirements of 10 CFR 835 as implemented by the Los Alamos National Laboratory procedure P121. The analyses indicate that extremity doses would also meet design requirements. Dose-rate calculations were performed using the radiation transport code MCNP5 and doses were estimated using a time-motion study developed in consort with the subject matter expert. A copy of this report and all supporting documentation are located on the Radiological Engineering server at Y:\\Rad Engineering\\2013 PROJECTS\\TA-55 Clear Line.

Flavonoid rutin increases thyroid iodide uptake in rats.

Directory of Open Access Journals (Sweden)

Carlos Frederico Lima Gonçalves

Full Text Available Thyroid iodide uptake through the sodium-iodide symporter (NIS is not only an essential step for thyroid hormones biosynthesis, but also fundamental for the diagnosis and treatment of different thyroid diseases. However, part of patients with thyroid cancer is refractory to radioiodine therapy, due to reduced ability to uptake iodide, which greatly reduces the chances of survival. Therefore, compounds able to increase thyroid iodide uptake are of great interest. It has been shown that some flavonoids are able to increase iodide uptake and NIS expression in vitro, however, data in vivo are lacking. Flavonoids are polyhydroxyphenolic compounds, found in vegetables present in human diet, and have been shown not only to modulate NIS, but also thyroperoxidase (TPO, the key enzyme in thyroid hormones biosynthesis, besides having antiproliferative effect in thyroid cancer cell lines. Therefore, we aimed to evaluate the effect of some flavonoids on thyroid iodide uptake in Wistar rats in vivo. Among the flavonoids tested, rutin was the only one able to increase thyroid iodide uptake, so we decided to evaluate the effect of this flavonoid on some aspects of thyroid hormones synthesis and metabolism. Rutin led to a slight reduction of serum T4 and T3 without changes in serum thyrotropin (TSH, and significantly increased hypothalamic, pituitary and brown adipose tissue type 2 deiodinase and decreased liver type 1 deiodinase activities. Moreover, rutin treatment increased thyroid iodide uptake probably due to the increment of NIS expression, which might be secondary to increased response to TSH, since TSH receptor expression was increased. Thus, rutin might be useful as an adjuvant in radioiodine therapy, since this flavonoid increased thyroid iodide uptake without greatly affecting thyroid function.

Potassium Iodide

Science.gov (United States)

... certain other liquids including low-fat white or chocolate milk, flat soda, orange juice, raspberry syrup, or ... Potassium iodide may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away: swollen glands metallic taste in the ...

Molecular localisation of americium, technetium and cesium in edible marine animals. Their metabolic behavior and their consequences

International Nuclear Information System (INIS)

Pieri, J.; Goudard, F.; Milcent, M.C.

1992-01-01

We show the molecular behavior of americium, technetium and cesium on the chromatographic pattern of each cytosol in the digestive gland of eel and lobster. The contamination by cadmium seems to compete with americium in the fractions of MW 10,000. Cesium shows an ionic behavior. (author)

Americium/curium bushing melter drain tests

International Nuclear Information System (INIS)

Smith, M.E.; Hardy, B.J.; Smith, M.E.

1997-01-01

Americium and curium were produced in the past at the Savannah River Site (SRS) for research, medical, and radiological applications. They have been stored in a nitric acid solution in an SRS reprocessing facility for a number of years. Vitrification of the americium/curium (Am/Cm) solution will allow the material to be safely stored or transported to the DOE Oak Ridge Reservation. Oak Ridge is responsible for marketing radionuclides for research and medical applications. The bushing melter technology being used in the Am/Cm vitrification research work is also under consideration for the stabilization of other actinides such as neptunium and plutonium. A series of melter drain tests were conducted at the Savannah River Technology Center to determine the relationship between the drain tube assembly operating variables and the resulting pour initiation times, glass flowrates, drain tube temperatures, and stop pour times. Performance criteria such as ability to start and stop pours in a controlled manner were also evaluated. The tests were also intended to provide support of oil modeling of drain tube performance predictions and thermal modeling of the drain tube and drain tube heater assembly. These drain tests were instrumental in the design of subsequent melter drain tube and drain tube heaters for the Am/Cm bushing melter, and therefore in the success of the Am/Cm vitrification and plutonium immobilization programs

Prevention of organic iodide formation in BWR's

International Nuclear Information System (INIS)

Karjunen, T.; Laitinen, T.; Piippo, J.; Sirkiae, P.

1996-01-01

During an accident, many different forms of iodine may emerge. Organic iodides, such as methyl iodide and ethyl iodide, are relatively volatile, and thus their appearance leads to increased concentration of gaseous iodine. Since organic iodides are also relatively immune to most accident mitigation measures, such as sprays and filters, they can affect the accident source term significantly even when only a small portion of iodine is in organic form. Formation of organic iodides may not be limited by the amount of organic substances available. Excessive amounts of methane can be produced, for example, during oxidation of boron carbide, which is used in BWR's as a neutron absorber material. Another important source is cable insulation. In a BWR, a large quantity of cables is placed below the pressure vessel. Thus a large quantity of pyrolyse gases will be produced, should the vessel fail. Organic iodides can be formed as a result of many different reactions, but at least in certain conditions the main reaction takes place between an organic radical produced by radiolysis and elemental iodine. A necessary requirement for prevention of organic iodide production is therefore that the pH in the containment water pools is kept high enough to eliminate formation of elemental iodine. In a typical BWR the suppression pool water is usually unbuffered. As a result, the pH may be dominated by chemicals introduced during an accident. If no system for adding basic chemicals is operable, the main factor affecting pool water pH may be hydrochloric acid released during cable degradation. Should this occur, the conditions could be very favorable for production of elemental iodine and, consequently, formation of organic iodides. Although high pH is necessary for iodine retention, it could have also adverse effects. High pH may, for example, accelerate corrosion of containment materials and alter the characteristics of the solid corrosion products. (author) 6 figs., 1 tab., 13 refs

Electric resistivity of 241-americium and 244-curium metals. Creation of defects and isochronous annealing of 241-americium metal after self-irradiation

International Nuclear Information System (INIS)

Schenkel, R.

1977-03-01

The temperature dependence of the electrical resistivity of thin films of bulk 241 Am metal were measured between 300 and 4.5 K. The room temperature resistivity was found to be 68.90μΩcm. At room temperature the electrical resistivity of americium increases with pressure (3% up to 13 kbar). The application of 13 kbar pressure did not change the low temperature power law in the electrical resistivity. The resistivity vs temperature curve can be explained by assuming s-d scattering of conduction electrons. The localized 5f electrons are considered to be about 5eV below the Fermi level. Americium therefore should be the first lanthanide-like element in the actinide series. The defect production due to self-irradiation damage was studied by measuring the increase of the resistivity at 4.2 K over a period of 738 h. A saturation resistivity of 16.036 μΩcm was found corresponding to a defect concentration of about 0.22 a/o. After isochronal annealing two recovery stages were observed at about 65 and 145 K. The two stages shift with increasing initial defect concentration to lower temperatures. Estimates of the activation energies and the reaction order were made and possible defect reactions suggested. The magnetic contribution to the electrical resistivity of curium, which shows an antiferromagnetic transition at 52.5 k, was obtained by subtracting the resistivity of americium (to be considered as phonon part). Comparison with theoretical models were made. At low temperatures the measurements are strongly affected by self-irradiation damage [drho/dt(t=0)=9.8μΩcm/h

Kinetic method for determination of iodide ion ultramicroamounts. Kineticheskij sposob opredeleniya ul'tramikrokolichestv iodid-ionov

Energy Technology Data Exchange (ETDEWEB)

Barkauskas, Yu K; Ramanauskas, Eh I

1980-04-03

A kinetic method for iodides ultramicroamount determination from their catalytic effect on oxidation of malachite green with chloramine B in the presence of acetone at pH 5.78+-0.3 is developed. The induction period of the reaction is determined from a change in the redox potential of the system. The induction period is proportional to the iodides concentration. Determination limit of iodides is equal to 4 ..mu..g iodide per 100 l of solution. More than 10/sup 5/-multiple amounts of K/sup +/, Na/sup +/, NH/sub 4//sup +/, Ba/sup 2 +/, Al/sup 3 +/, Cu/sup 2 +/, Mg/sup 2 +/, SO/sub 4//sup 2 -/, Cl/sup -/, MoO/sub 4//sup 2 -/, NO/sub 3//sup -/, ClO/sub 3//sup -/, IO/sub 3//sup -/, IO/sub 4//sup -/, ClO/sub 4//sup -/, BrO/sub 3//sup -/; 10/sup 5/-10/sup 3/-multiple amounts of Cr/sup 3 +/, Fe/sup 3 +/, Sn/sup 2 +/, S/sup 2 -/, MnO/sub 4//sup -/, NO/sub 2//sup -/ etc. do not interfere with the determination, while 10-multiple amounts of SCN, 0.2-multiple quantities of Ag/sup +/, Hg/sub 2//sup 2 +/ do.

In Vitro Bioavailability Study of an Antiviral Compound Enisamium Iodide

Directory of Open Access Journals (Sweden)

Eleonore Haltner-Ukomadu

2018-01-01

Full Text Available An investigation into the biopharmaceutics classification and a study of the in vitro bioavailability (permeability and solubility of the antiviral compound enisamium iodide (4-(benzylcarbamoyl-1-methylpyridinium iodide were carried out. The solubility of enisamium iodide was determined in four different buffers. Apparent intestinal permeability (Papp of enisamium iodide was assessed using human colon carcinoma (Caco-2 cells at three concentrations. The solubility of enisamium iodide in four buffer solutions from pH 1.2 to 7.5 is about 60 mg/mL at 25 °C, and ranges from 130 to 150 mg/mL at 37 °C, depending on the pH. Based on these results, enisamium iodide can be classified as highly soluble. Enisamium iodide demonstrated low permeability in Caco-2 experiments in all tested concentrations of 10–100 μM with permeability coefficients between 0.2 × 10−6 cm s−1 and 0.3 × 10−6 cm s−1. These results indicate that enisamium iodide belongs to class III of the Biopharmaceutics Classification System (BCS due to its high solubility and low permeability. The bioavailability of enisamium iodide needs to be confirmed in animal and human studies.

The rapid determination of americium curium, and uranium in urine by ultrafiltration

International Nuclear Information System (INIS)

Stradling, G.N.; Popplewell, D.S.; Ham, G.J.; Griffin, R.

1975-01-01

The rapid ultrafiltration method developed for the assay of plutonium has been extended to the determination of americium, curium and uranium in urine. The limits of detection for americium and curium, and uranium are 0.09 and 0.12 dm -1 l -1 respectively, and the analysis time excluding counting less than 2 hours. The method can therefor be effectively used as a rapid screening procedure. When the reference level for plutonium is exceeded, the α activity may require to be characterised. The single ultrafiltration technique must be modified for turbid urine samples. The method is inappropriate, except for uranium, when the urine contains DTPA. (author)

Study of radiation formation of methyl-iodide Part 2

International Nuclear Information System (INIS)

Bartonicek, B.; Schweiner, Z.; Bednar, J.; Hladky, E.

1975-01-01

Purified methane, ethylene, iodine, methyl iodide, ethyl iodide and hydrogen iodide were irradiated and/or pyrolyzed in Pyrex ampoules by 60 Co-γ-radiation at temperatures between 150 and 450 deg C. The results on radiolysis and pyrolysis were as follows: 1., The most thermally stable product is hydrogen iodide in which already at 450 deg C essen-tially all originally present iodine appears. 2., The radiolytic formation of methyl iodide and hydrogen iodide is positively influenced by the rise in temperature, This and the absolute values of yields indicate a chain mechanism of radiolytic (and pyrolytic) decomposition of the mixture. 3., The ratio of equilibrium concentrations [HI]/[CH 3 I] increases with increasing temperature of pyrolysis showing that HI is the end product of the thermal chain reaction. Methyl iodide is likely to contribute (by its thermal decomposition) to the initiation and propagation of this chain reaction. 4., The negligible temperature dependence of G(H 2 ) and the absence of molecular hydrogen among the products of pyrolytic decomposition of methane-iodine mixtures shows, that (up to 450 deg C) H atoms do not play any role in the thermal chain decomposition of these mixtures. (K.A.)

Speciation and bioavailability of plutonium and americium in the Irish Sea and other marine ecosystems

International Nuclear Information System (INIS)

Vives i Batlle, J.

1993-12-01

Since the late 1960s, the Irish Sea has become a repository for a variety of radio-elements originating mainly in discharges from the British Nuclear Fuels (BNF) plc. Sellafield reprocessing complex located on the Cumbrian coast. In particular, transuranium nuclides such as plutonium, americium and curium (the main constituents of the α-emitting discharges) have become incorporated into every marine compartment by a variety of mechanisms, many of which are not well understood. Although extensive studies have been carried out in the near-field (eastern Irish Sea, especially in the vicinity of the discharge point and collateral muddy sediments), comparatively little had been done to assess the long-term behaviour and bioavailability of plutonium and americium in the far-field, e.g., the western Irish Sea, prior to the present study. In this dissertation, the results of an extensive research programme, undertaken in order to improve and refine our understanding of the behaviour of plutonium and americium in the marine environment, are presented. Specifically, the thesis details the results of (and conclusions deduced from) a series of experiments in which the physical and chemical speciation, colloidal association, mobility and bioavailability of plutonium and americium were examined in diverse environments including the Irish Sea and the Mediterranean. (author)

Aqueous-gas phase partitioning and hydrolysis of organic iodides

International Nuclear Information System (INIS)

Glowa, G.A.; Wren, J.C.

2003-01-01

The volatility and decomposition of organic iodides in a reactor containment building are important parameters to consider when assessing the potential consequences of a nuclear reactor accident. However, there are few experimental data available for the volatilities (often reported as partition coefficients) or few rate constants regarding the decomposition (via hydrolysis) of organic iodides. The partition coefficients and hydrolysis rate constants of eight organic iodides, having a range of molecular structures, have been measured in the current studies. This data, and data accumulated in the literature, have been reviewed and discussed to provide guidelines for appropriate organization of organic iodides for the purpose of modelling iodine behaviour under postulated nuclear reactor accident conditions. After assessment of the partition coefficients and their temperature dependences of many classes of organic compounds, it was found that organic iodides could be divided into two categories based upon their volatility relative to molecular iodine. Similarly, hydrolysis rates and their temperature dependences are assigned to the two categories of organic iodides. (author)

Structural characterisations and mechanistic investigations of the selective dissolution of americium by the ferricyanide ions in alkaline media. Application for the partitioning americium curium

International Nuclear Information System (INIS)

Fouchard, Sebastien

2000-01-01

Americium exhibits a high solubility form in basic media under oxidant conditions, unlike the other Transplutonium elements (TPE). This property can be used in the frame of High Level Liquid Waste (HLLW) treatment in order to extract preferentially the americium element, the main responsible of the long term radiotoxicity of the nuclear waste. This soluble compound can be obtained by addition of a concentrated basic solution of Fe(CN) 6 3- ions on Am(OH) 3 precipitates. This technique enables a rapid extraction of Am by the synthesis of this soluble form in alkaline solutions. Under these conditions, the other TPE remain in the solid state as trivalent hydroxide solids, strongly insoluble. In the case of dissolutions involving large amounts of Am(OH) 3 , the formation of the soluble complex is concomitant with the appearance of a reddish precipitate in the basic solution. Dissolution experiments which were carried out on this solid in NaOH/Fe(CN) 6 3- have demonstrated the dependency of the solubility equilibria with the media. Spectroscopic studies (UV Visible, XAS) on the precipitate have enabled the determination of the chemical structure and the oxidation state of the americium in the solid: Na 2 Am(V)O 2 (OH) 3 ,nH 2 O. Electrochemical studies on the americium solution have confirmed that the oxidation of Am(OH) 3 by the Fe(CN) 6 3- ions in basic media could only lead to the pentavalent form. A stoichiometric study carries out between a AmO 2 + ion and one Fe(CN) 6 3- ion and the spectroscopic characterisation of this reaction have demonstrated that the Fe(CN) 6 3- ion didn't remain as an un-complexed form in solution after the alkaline mixing. These results tend to prove that this dissolution of Am(OH) 3 is much more complex than a simple oxidation by the Fe(CN) 6 3- ions. The existence of molecular interactions between AmO 2 + and Fe(CN) 6 3- has been postulated and a mechanistic scheme has been proposed in order to explain the appearance of the soluble

The weak acid resin process: a dustless conversion route for the synthesis of americium bearing-blanket precursors

International Nuclear Information System (INIS)

Picart, S.; Gauthe, A.; Parant, P.; Remy, E.; Jobelin, I.; Pomared, J.M.; Grangaud, P.; Dauby, J.; Delahaye, T.; Caisso, M.; Bataille, M.; Bayle, J.P.; Frost, C.; Delage, C.; Martin, C.L.; Ayral, E.

2016-01-01

Mixed uranium-americium oxides are one of the materials envisaged for Americium Bearing Blankets dedicated to transmutation in fast neutron reactors. Conversion and fabrication processes are currently developed to make those materials in the form of dense and homogeneous oxide ceramic pellets or dense granulates incorporating uranium and americium. Their development points out the need of a simplified and optimized process which could lower hazards linked to dust generation of highly contaminating and irradiating compounds and facilitate material transfer in remote handling operations. This reason motivated the development of innovative 'dustless' route such as the Weak Acid Resin route (WAR) which provides the oxide precursors in the form of sub-millimeter-sized microspheres with optimal flowability and limits dust generation during conversion and fabrication steps. This study is thus devoted to the synthesis of mixed uranium-americium oxide microspheres by the WAR process and to the characterization of such precursors. This work also deals with their application to the fabrication of dense or porous pellets and with their potential use as dense spherules to make Sphere-Pac fuel. (authors)

The weak acid resin process: a dustless conversion route for the synthesis of americium bearing-blanket precursors

Energy Technology Data Exchange (ETDEWEB)

Picart, S.; Gauthe, A.; Parant, P.; Remy, E.; Jobelin, I.; Pomared, J.M.; Grangaud, P.; Dauby, J.; Delahaye, T. [CEA, Centre de Marcoule, DEN/MAR/DRCP, F-30207 Bagnols-sur-Ceze (France); Caisso, M.; Bataille, M.; Bayle, J.P. [CEA, Centre de Marcoule, DEN/MAR/DTEC, F-30207 Bagnols-sur-Ceze (France); Frost, C. [CEA, Centre de Marcoule, DEN/MAR/DRCP, F-30207 Bagnols-sur-Ceze (France); Institut Europeen des Membranes, CNRS-ENSCM-UM, CC47, University of Montpellier, F-34095 Montpellier (France); Delage, C. [CEA, Centre de Cadarache, DEN/CAD/DEC, Saint-Paul-lez-Durance (France); Martin, C.L. [Univ. Grenoble Alpes, CNRS, SIMAP, F-38000 Grenoble (France); Ayral, E. [Institut Europeen des Membranes, CNRS-ENSCM-UM, CC47, University of Montpellier, F-34095 Montpellier (France)

2016-07-01

Mixed uranium-americium oxides are one of the materials envisaged for Americium Bearing Blankets dedicated to transmutation in fast neutron reactors. Conversion and fabrication processes are currently developed to make those materials in the form of dense and homogeneous oxide ceramic pellets or dense granulates incorporating uranium and americium. Their development points out the need of a simplified and optimized process which could lower hazards linked to dust generation of highly contaminating and irradiating compounds and facilitate material transfer in remote handling operations. This reason motivated the development of innovative 'dustless' route such as the Weak Acid Resin route (WAR) which provides the oxide precursors in the form of sub-millimeter-sized microspheres with optimal flowability and limits dust generation during conversion and fabrication steps. This study is thus devoted to the synthesis of mixed uranium-americium oxide microspheres by the WAR process and to the characterization of such precursors. This work also deals with their application to the fabrication of dense or porous pellets and with their potential use as dense spherules to make Sphere-Pac fuel. (authors)

Linking loss of sodium-iodide symporter expression to DNA damage

Energy Technology Data Exchange (ETDEWEB)

Lyckesvärd, Madeleine Nordén [Sahlgrenska Cancer Center, University of Gothenburg, Göteborg (Sweden); Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg (Sweden); Kapoor, Nirmal [Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg (Sweden); Ingeson-Carlsson, Camilla; Carlsson, Therese [Sahlgrenska Cancer Center, University of Gothenburg, Göteborg (Sweden); Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg (Sweden); Karlsson, Jan-Olof [Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg (Sweden); Postgård, Per; Himmelman, Jakob; Forssell-Aronsson, Eva [Department of Radiation Physics, University of Gothenburg, Göteborg (Sweden); Hammarsten, Ola [Department of Clinical Chemistry, University of Gothenburg, Göteborg (Sweden); Nilsson, Mikael, E-mail: mikael.nilsson@gu.se [Sahlgrenska Cancer Center, University of Gothenburg, Göteborg (Sweden); Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg (Sweden)

2016-05-15

Radiotherapy of thyroid cancer with I-131 is abrogated by inherent loss of radioiodine uptake due to loss of sodium iodide symporter (NIS) expression in poorly differentiated tumor cells. It is also known that ionizing radiation per se down-regulates NIS (the stunning effect), but the mechanism is unknown. Here we investigated whether loss of NIS-mediated iodide transport may be elicited by DNA damage. Calicheamicin, a fungal toxin that specifically cleaves double-stranded DNA, induced a full scale DNA damage response mediated by the ataxia-telangiectasia mutated (ATM) kinase in quiescent normal thyrocytes. At sublethal concentrations (<1 nM) calicheamicin blocked NIS mRNA expression and transepithelial iodide transport as stimulated by thyrotropin; loss of function occurred at a much faster rate than after I-131 irradiation. KU-55933, a selective ATM kinase inhibitor, partly rescued NIS expression and iodide transport in DNA-damaged cells. Prolonged ATM inhibition in healthy cells also repressed NIS-mediated iodide transport. ATM-dependent loss of iodide transport was counteracted by IGF-1. Together, these findings indicate that NIS, the major iodide transporter of the thyroid gland, is susceptible to DNA damage involving ATM-mediated mechanisms. This uncovers novel means of poor radioiodine uptake in thyroid cells subjected to extrinsic or intrinsic genotoxic stress. - Highlights: • DNA damage inhibits polarized iodide transport in normal thyroid cells. • Down-regulation of NIS expression is mediated by activation of the ATM kinase. • Long-term ATM inhibition also represses NIS-mediated iodide transport. • IGF-1 rescues NIS expression and iodide transport in DNA-damaged cells.

Linking loss of sodium-iodide symporter expression to DNA damage

International Nuclear Information System (INIS)

Lyckesvärd, Madeleine Nordén; Kapoor, Nirmal; Ingeson-Carlsson, Camilla; Carlsson, Therese; Karlsson, Jan-Olof; Postgård, Per; Himmelman, Jakob; Forssell-Aronsson, Eva; Hammarsten, Ola; Nilsson, Mikael

2016-01-01

Radiotherapy of thyroid cancer with I-131 is abrogated by inherent loss of radioiodine uptake due to loss of sodium iodide symporter (NIS) expression in poorly differentiated tumor cells. It is also known that ionizing radiation per se down-regulates NIS (the stunning effect), but the mechanism is unknown. Here we investigated whether loss of NIS-mediated iodide transport may be elicited by DNA damage. Calicheamicin, a fungal toxin that specifically cleaves double-stranded DNA, induced a full scale DNA damage response mediated by the ataxia-telangiectasia mutated (ATM) kinase in quiescent normal thyrocytes. At sublethal concentrations (<1 nM) calicheamicin blocked NIS mRNA expression and transepithelial iodide transport as stimulated by thyrotropin; loss of function occurred at a much faster rate than after I-131 irradiation. KU-55933, a selective ATM kinase inhibitor, partly rescued NIS expression and iodide transport in DNA-damaged cells. Prolonged ATM inhibition in healthy cells also repressed NIS-mediated iodide transport. ATM-dependent loss of iodide transport was counteracted by IGF-1. Together, these findings indicate that NIS, the major iodide transporter of the thyroid gland, is susceptible to DNA damage involving ATM-mediated mechanisms. This uncovers novel means of poor radioiodine uptake in thyroid cells subjected to extrinsic or intrinsic genotoxic stress. - Highlights: • DNA damage inhibits polarized iodide transport in normal thyroid cells. • Down-regulation of NIS expression is mediated by activation of the ATM kinase. • Long-term ATM inhibition also represses NIS-mediated iodide transport. • IGF-1 rescues NIS expression and iodide transport in DNA-damaged cells.

Potassium iodide capsule treatment of feline sporotrichosis.

Science.gov (United States)

Reis, Erica G; Gremião, Isabella D F; Kitada, Amanda A B; Rocha, Raphael F D B; Castro, Verônica S P; Barros, Mônica B L; Menezes, Rodrigo C; Pereira, Sandro A; Schubach, Tânia M P

2012-06-01

Sporotrichosis is a mycosis caused by Sporothrix schenckii. The most affected animal is the cat; it has played an important role in the zoonotic transmission of this disease, especially in Rio de Janeiro, Brazil, since 1998. In order to evaluate the treatment of feline sporotrichosis with potassium iodide, an observational cohort was conducted in 48 cats with sporotrichosis at Instituto de Pesquisa Clínica Evandro Chagas, Fiocruz. All cats received potassium iodide capsules, 2.5 mg/kg to 20 mg/kg q24h. The cure rate was 47.9%, treatment failure was 37.5%, treatment abandonment was 10.4% and death was 4.2%. Clinical adverse effects were observed in 52.1% of the cases. Thirteen cats had a mild increase in hepatic transaminase levels during the treatment, six of them presented clinical signs suggestive of hepatotoxicity. Compared to previous studies with itraconazole and iodide in saturated solution, potassium iodide capsules are an alternative for feline sporotrichosis treatment.

Higher Americium Oxidation State Research Roadmap

Energy Technology Data Exchange (ETDEWEB)

Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Law, Jack D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Goff, George S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lumetta, Gregg J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shehee, Thomas C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hobbs, David T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-12-18

The partitioning of hexavalent Am from dissolved nuclear fuel requires the ability to efficiently oxidize Am(III) to Am(VI) and to maintain that oxidation state for a length of time sufficient to perform the separation. Several oxidants have been, or are being developed. Chemical oxidants include Ag-catalyzed ozone, Ag-catalyzed peroxydisulfate, Cu(III) periodate, and sodium bismuthate. Hexavalent americium has also now successfully been prepared by electrolysis, using functionalized electrodes. So-called auto-reduction rates of Am(VI) are sufficiently slow to allow for separations. However, for separations based on solvent extraction or ion exchange using organic resins, the high valence state must be maintained under the reducing conditions of the organic phase contact, and a holding oxidant is probably necessary. Until now, only Cu(III) periodate and sodium bismuthate oxidation have been successfully combined with solvent extraction separations. Bismuthate oxidation provided the higher DAm, since it acts as its own holding oxidant, and a successful hot test using centrifugal contactors was performed. For the other oxidants, Ag-catalyzed peroxydisulfate will not oxidize americium in nitric acid concentrations above 0.3 M, and it is not being further investigated. Peroxydisulfate in the absence of Ag catalysis is being used to prepare Am(V) in ion exchange work, discussed below. Preliminary work with Ag-catalyzed ozone has been unsuccessful for extractions of Am(VI) from 6.5 M HNO3, and only one attempt at extraction, also from 6.5 M HNO3, using the electrolytic oxidation has been attempted. However, this high acid concentration was based on the highest Am extraction efficiency using the bismuthate oxidant; which is only sparingly soluble, and thus the oxidation yield is based on bismuthate solubility. Lower acid concentrations may be sufficient with alternative oxidants and work with Ag-ozone, Cu(III) and electrolysis is on-going. Two non

Solubility of Plutonium (IV) Oxalate During Americium/Curium Pretreatment

International Nuclear Information System (INIS)

Rudisill, T.S.

1999-01-01

Approximately 15,000 L of solution containing isotopes of americium and curium (Am/Cm) will undergo stabilization by vitrification at the Savannah River Site (SRS). Prior to vitrification, an in-tank pretreatment will be used to remove metal impurities from the solution using an oxalate precipitation process. Material balance calculations for this process, based on solubility data in pure nitric acid, predict approximately 80 percent of the plutonium in the solution will be lost to waste. Due to the uncertainty associated with the plutonium losses during processing, solubility experiments were performed to measure the recovery of plutonium during pretreatment and a subsequent precipitation process to prepare a slurry feed for a batch melter. A good estimate of the plutonium content of the glass is required for planning the shipment of the vitrified Am/Cm product to Oak Ridge National Laboratory (ORNL).The plutonium solubility in the oxalate precipitation supernate during pretreatment was 10 mg/mL at 35 degrees C. In two subsequent washes with a 0.25M oxalic acid/0.5M nitric acid solution, the solubility dropped to less than 5 mg/mL. During the precipitation and washing steps, lanthanide fission products in the solution were mostly insoluble. Uranium, and alkali, alkaline earth, and transition metal impurities were soluble as expected. An elemental material balance for plutonium showed that greater than 94 percent of the plutonium was recovered in the dissolved precipitate. The recovery of the lanthanide elements was generally 94 percent or higher except for the more soluble lanthanum. The recovery of soluble metal impurities from the precipitate slurry ranged from 15 to 22 percent. Theoretically, 16 percent of the soluble oxalates should have been present in the dissolved slurry based on the dilution effects and volumes of supernate and wash solutions removed. A trace level material balance showed greater than 97 percent recovery of americium-241 (from the beta dec

Prevention of organic iodide formation in BWR`s

Energy Technology Data Exchange (ETDEWEB)

Karjunen, T [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland); Laitinen, T; Piippo, J; Sirkiae, P [VTT Manufacturing Technology (Finland)

1996-12-01

During an accident, many different forms of iodine may emerge. Organic iodides, such as methyl iodide and ethyl iodide, are relatively volatile, and thus their appearance leads to increased concentration of gaseous iodine. Since organic iodides are also relatively immune to most accident mitigation measures, such as sprays and filters, they can affect the accident source term significantly even when only a small portion of iodine is in organic form. Formation of organic iodides may not be limited by the amount of organic substances available. Excessive amounts of methane can be produced, for example, during oxidation of boron carbide, which is used in BWR`s as a neutron absorber material. Another important source is cable insulation. In a BWR, a large quantity of cables is placed below the pressure vessel. Thus a large quantity of pyrolyse gases will be produced, should the vessel fail. Organic iodides can be formed as a result of many different reactions, but at least in certain conditions the main reaction takes place between an organic radical produced by radiolysis and elemental iodine. A necessary requirement for prevention of organic iodide production is therefore that the pH in the containment water pools is kept high enough to eliminate formation of elemental iodine. In a typical BWR the suppression pool water is usually unbuffered. As a result, the pH may be dominated by chemicals introduced during an accident. If no system for adding basic chemicals is operable, the main factor affecting pool water pH may be hydrochloric acid released during cable degradation. Should this occur, the conditions could be very favorable for production of elemental iodine and, consequently, formation of organic iodides. Although high pH is necessary for iodine retention, it could have also adverse effects. High pH may, for example, accelerate corrosion of containment materials and alter the characteristics of the solid corrosion products. (author) 6 figs., 1 tab., 13 refs.

Analysis of americium, plutonium and technetium solubility in groundwater

International Nuclear Information System (INIS)

Takeda, Seiji

1999-08-01

Safety assessments for geologic disposal of radioactive waste generally use solubilities of radioactive elements as the parameter restricting the dissolution of the elements from a waste matrix. This study evaluated americium, plutonium and technetium solubilities under a variety of geochemical conditions using the geochemical model EQ3/6. Thermodynamic data of elements used in the analysis were provided in the JAERI-data base. Chemical properties of both natural groundwater and interstitial water in buffer materials (bentonite and concrete) were investigated to determine the variations in Eh, pH and ligand concentrations (CO 3 2- , F - , PO 4 3- , SO 4 2- , NO 3 - and NH 4 + ). These properties can play an important role in the complexation of radioactive elements. Effect of the groundwater chemical properties on the solubility and formation of chemical species for americium, plutonium and technetium was predicted based on the solubility analyses under a variety of geochemical conditions. The solubility and speciation of the radioactive elements were estimated, taking into account the possible range of chemical compositions determined from the groundwater investigation. (author)

Contemporary state of plutonium and americium in the soils of Palesse state radiation-ecological reserve

International Nuclear Information System (INIS)

Papenia, M.V.; Sokolik, G.A.; Ovsiannikova, S.V.; Voinikava, E.V.; Svirschevsky, S.F.; Brown, J.; Skipperud, L.

2010-01-01

Full text: At present, the most important alpha-emitting radionuclides of Chernobyl origin are Pu 238, Pu 239, Pu 240 and Am 241. They are classified as the most dangerous group of radionuclides in view of the long half-lives and high radiotoxicity. The main part of alpha-emitted radionuclides is located within the Palesse State Radiation-Ecological Reserve. One of the most important factors determining the radioecological situation in the contaminated ecosystems is the physicochemical forms of radionuclides in a soil medium. Radionuclide species determine the radionuclide entrance into the soil solutions, their redistribution in soil profiles and the 'soil - plant' and the 'soil - surface, ground or underground water' systems as well as spreading beyond the contaminated area. The present work is devoted to investigation of state and migration ability of plutonium and americium in soils of the Palesse state radiation-ecological reserve after more than 20 years from the Chernobyl accident. The objects of investigation were mineral and organic soils sampled in 2008 with the step of 5 cm to the depth of 25-30 cm. The forms of plutonium and americium distinguishing by association with the different components of soil and by potential for migration in the soil medium were studied using the method of sequential selective extraction according to the modified Tessier scheme. Activities of Pu 238, Pu 239, Pu 240 and Am 241 in the samples were determined by the method of radiochemical analysis with alpha-spectrometer radionuclide identification. The dominant part of plutonium and americium in the soils is in immobile forms. Nowadays, radionuclide portions in water soluble and reversibly bound forms do not exceed 9.4 % of radionuclide content in the soil. In mineral soil samples, the radionuclide portions in these fractions exceed the corresponding portions in organic ones. In both mineral and organic soils, the portions of mobile americium are higher than plutonium. The

Contribution to the study of higher valency states of americium

International Nuclear Information System (INIS)

Langlet, Jean.

1976-01-01

Study of the chemistry of the higher valencies of americium in aqueous solutions and especially the autoreduction phenomenon. First a purification method of americium solutions is studied by precipitation, solvent extraction and ion exchange chromatography. Studies of higher valency states chemical properties are disturbed by the autoreduction phenomenon changing Am VI and Am V in Am III more stable. Stabilization of higher valency states, characterized by a steady concentration of Am VI in solution, can be done by complexation of Am VI and Am V ions or by a protecting effect of foreign ions. The original medium used has a complexing effect by SO 4 2- ions and a protecting effect by the system S 2 O 8 2- -Ag + consuming H 2 O 2 main reducing agent produced by water radiolysis. These effects are shown by the study of Am VI in acid and basic solutions. A mechanism of the stabilization effect is given [fr

Lifetime followup of the 1976 americium accident victim: [Final report

International Nuclear Information System (INIS)

Breitenstein, B.D. Jr.; Palmer, H.E.

1988-05-01

This report describes the 11 year medical course of Harold R. McCluskey, a Hanford nuclear chemical operator, who, at age 64, was involved in an accident in an americium recovery facility in August 1976. As a result of the accident, he was heavily contaminated with americium (Am-241), sustained a substantial internal deposition of this isotope, and was burned with concentrated nitric acid and injured by flying debris about the face and neck. The immediate and long-term medical care is summarized, including decontamination procedures, chelation therapy, and routine and special clinical laboratories studies. The estimates of the operator's Am-241 deposition, post accident and during the remainder of his life and the special techniques and equipment used to make the estimates, are reported. Post-accident, the total amount of Am-241 excreted in his urine and feces was 41 MBq (1.1 mCi). He died of complications of chronic coronary artery disease on August 17, 1987. 20 refs., 2 figs

Plant uptake of americium, curium, and the chemical analog neodymium

International Nuclear Information System (INIS)

Weimer, W.C.; Laul, J.C.; Kutt, J.C.; Bondietti, E.A.

1977-01-01

The plant uptake from several bulk soils has been determined for neodymium, a chemical analog to the transuranium elements americium and curium, and several other native rare earth elements as well. These investigations have demonstrated that neodymium, which has very similar chemical properties to amercium and curium and should have a similar environmental behavior, does behave indistinguishably under both laboratory and field conditions. The uptake of the weathered or mobile forms of these elements from soils is expected to be governed primarily by their identical oxidation states and nearly identical ionic radii. This hypothesis is strongly supported by the chondritic (primordial) normalized rare earth element patterns in several plants. In these samples, the entire series of rare earth elements behaves as a smooth function of the REE ionic radii, as is also seen in the contiguous soils. This behavior suggests that the plant uptake of other ions with similar chemical properties (i.e., americium and curium) would also be governed by ionic size and charge

Kinetics of [123I]iodide uptake and discharge by perchlorate in studies of inhibition of iodide binding by antithyroid drugs

International Nuclear Information System (INIS)

McCruden, D.C.; Connell, J.M.C.; Alexander, W.D.; Hilditch, T.E.

1985-01-01

Thyroidal binding of iodide was studied by kinetic analysis of [ 123 ]iodide uptake and its discharge by perchlorate in 80 hyperthyroid subjects receiving antithyroid drug therapy. Five dosage regimens ranging from 5 mg carbimazole twice daily to 15 mg methimazole twice daily were studied. Binding inhibition was estimated at 5-7 h after drug as an index of the mean effect of the 12 hourly regimen. In all cases, except one in the lowest dose group, binding was found to be markedly reduced with mean binding rates ranging from 0.002 to 0.020 min -1 (normal > 0.15 min -1 ). The net clearance of iodide in the lowest dose group was reduced to a mean value near the upper limit of the euthyroid range, whereas in the highest dose group it lay at the lower limit of the euthyroid range. These results were reflected in the serum thyroid hormone response. There was a reducing incidence of inadequate control of hyperthyroidism and an increasing incidence of hypothyroidism with increasing thiourylene dose. The exit rate constant of free iodide for the various doses showed values from 0.048 to 0.055 min -1 . Correpsonding mean values for the discharge rate constant after perchlorate were 0.087 to 0.105 min -1 . This suggests that perchlorate increases the rate of iodide release from the thyroid gland. Studies at a later interval after drug (12-14 h) showed no change in discharge rate constant. This leads to the conclusion that perchlorate may further inhibit iodide binding in subjects receiving antithyroid drug therapy. (author)

Ingestion Pathway Transfer Factors for Plutonium and Americium

International Nuclear Information System (INIS)

Blanchard, A.

1999-01-01

Overall transfer factors for major ingestion pathways are derived for plutonium and americium. These transfer factors relate the radionuclide concentration in a given foodstuff to deposition on the soil. Equations describing basic relationships consistent with Regulatory Guide 1.109 are followed. Updated values and coefficients from IAEA Technical Reports Series No. 364 are used when a available. Preference is given to using factors specific to the Savannah River Site

Thermodynamic systematics of oxides of americium, curium, and neighboring elements

International Nuclear Information System (INIS)

Morss, L.R.

1984-01-01

Recently-obtained calorimetric data on the sesquioxides and dioxides of americium and curium are summarized. These data are combined with other properties of the actinide elements to elucidate the stability relationships among these oxides and to predict the behavior of neighboring actinide oxides. 45 references, 4 figures, 5 tables

Flavonoids, Thyroid Iodide Uptake and Thyroid Cancer-A Review.

Science.gov (United States)

Gonçalves, Carlos F L; de Freitas, Mariana L; Ferreira, Andrea C F

2017-06-12

Thyroid cancer is the most common malignant tumor of the endocrine system and the incidence has been increasing in recent years. In a great part of the differentiated carcinomas, thyrocytes are capable of uptaking iodide. In these cases, the main therapeutic approach includes thyroidectomy followed by ablative therapy with radioiodine. However, in part of the patients, the capacity to concentrate iodide is lost due to down-regulation of the sodium-iodide symporter (NIS), the protein responsible for transporting iodide into the thyrocytes. Thus, therapy with radioiodide becomes ineffective, limiting therapeutic options and reducing the life expectancy of the patient. Excessive ingestion of some flavonoids has been associated with thyroid dysfunction and goiter. Nevertheless, studies have shown that some flavonoids can be beneficial for thyroid cancer, by reducing cell proliferation and increasing cell death, besides increasing NIS mRNA levels and iodide uptake. Recent data show that the flavonoids apingenin and rutin are capable of increasing NIS function and expression in vivo. Herein we review literature data regarding the effect of flavonoids on thyroid cancer, besides the effect of these compounds on the expression and function of the sodium-iodide symporter. We will also discuss the possibility of using flavonoids as adjuvants for therapy of thyroid cancer.

Flavonoids, Thyroid Iodide Uptake and Thyroid Cancer—A Review

Science.gov (United States)

Gonçalves, Carlos F. L.; de Freitas, Mariana L.; Ferreira, Andrea C. F.

2017-01-01

Thyroid cancer is the most common malignant tumor of the endocrine system and the incidence has been increasing in recent years. In a great part of the differentiated carcinomas, thyrocytes are capable of uptaking iodide. In these cases, the main therapeutic approach includes thyroidectomy followed by ablative therapy with radioiodine. However, in part of the patients, the capacity to concentrate iodide is lost due to down-regulation of the sodium-iodide symporter (NIS), the protein responsible for transporting iodide into the thyrocytes. Thus, therapy with radioiodide becomes ineffective, limiting therapeutic options and reducing the life expectancy of the patient. Excessive ingestion of some flavonoids has been associated with thyroid dysfunction and goiter. Nevertheless, studies have shown that some flavonoids can be beneficial for thyroid cancer, by reducing cell proliferation and increasing cell death, besides increasing NIS mRNA levels and iodide uptake. Recent data show that the flavonoids apingenin and rutin are capable of increasing NIS function and expression in vivo. Herein we review literature data regarding the effect of flavonoids on thyroid cancer, besides the effect of these compounds on the expression and function of the sodium-iodide symporter. We will also discuss the possibility of using flavonoids as adjuvants for therapy of thyroid cancer. PMID:28604619

Photoluminescence Enhancement in Formamidinium Lead Iodide Thin Films

NARCIS (Netherlands)

Fang, Hong-Hua; Wang, Feng; Adjokatse, Sampson; Zhao, Ni; Loi, Maria Antonietta

2016-01-01

Formamidinium lead iodide (FAPbI(3)) has a broader absorption spectrum and better thermal stability than the most famous methylammonium lead iodide, thus exhibiting great potential for photovoltaic applications. In this report, the light-induced photoluminescence (PL) evolution in FAPbI(3) thin

Extraction separation of americium and curium. A review

International Nuclear Information System (INIS)

Petrzilova, H.

1976-11-01

A survey is given of extraction systems suitable for transplutonium element separation and preparation as well as for the practical application of their nuclear properties. Methods are discussed in detail of separating the actinide and the lanthanide fractions from fission and corrosion products and of separating americium from curium. The description is completed with flowsheets showing the separation of transplutonium elements from irradiated targets and waste solutions after spent fuel reprocessing. (L.K.)

Transmutation of americium and curium incorporated in zirconia-based host materials

International Nuclear Information System (INIS)

Raison, P.E.

2001-01-01

Presented are studies involving the incorporation of americium and curium in zirconia-based materials. First explored was the pseudo ternary system AmO 2 -ZrO 2 -Y 2 O 3 . It was determined that selected Y-CSZ materials can incorporate significant quantities of americium oxide and remain cubic single-phase. The cell parameters of these fluorite-type products were established to be linear with the AmO 2 content. The Cm 2 O 3 -ZrO 2 system was also investigated. It was found that at 25 mol% of CmO 1.5 , the Cm(III) stabilized zirconia in its cubic form (a = 5.21 ±0.01 Angstrom). At higher and lower concentrations, diphasic materials were encountered. At 50 mol% of CmO 1.5 , a pyrochlore oxide - Cm 2 Zr 2 O 7 - is formed (a = 10.63 ±0.02 Angstrom). (author)

Effect of nitrogen and oxygen on radiolysis of iodide solution

Energy Technology Data Exchange (ETDEWEB)

Karasawa, H; Endo, M [Hitachi Ltd., Power and Industrial System R+D Divisions, Ibaraki (Japan)

1996-12-01

The effect of nitrogen and oxygen on radiolysis of iodide solution was examined. Direct decomposition of nitrogen by {gamma}-radiation produced nitric acid to decrease a water pH. This resulted in the iodine formation in the radiolysis of iodide solution. Hydrogen peroxide was produced by the radiolysis of water containing oxygen. This worked a reducing agent to suppress the formation of iodine in the radiolysis of iodide solution. In the analytical model, fourteen iodine species were considered and reaction scheme consisted in 124 reactions. The analytical model could estimate the oxidation state of iodide ions. (author) 4 figs., 4 refs.

Research on solubility characteristics of gaseous methyl iodide

International Nuclear Information System (INIS)

Zhou Yanmin; Sun Zhongning; Gu Haifeng; Wang Junlong

2014-01-01

With the deionized water as the absorbent, the solubility characteristics of the gaseous methyl iodide were studied under different temperature and pressure conditions, using a dynamic measuring method. The results show that within the range of experiment parameters, namely temperature is below 80℃ and pressure is lower than 0.3 MPa, the physical dissolution process of gaseous methyl iodide in water obeys Henry's law. The solubility coefficient under different temperature and pressure conditions was calculated based on the measurement results. Further research indicates that at atmospheric pressure, the solubility coefficient of methyl iodide in water decreases exponentially with the increase of temperature. While the pressure changes from 0.1 MPa to 0.3 MPa with equal interval, the solubility coefficient also increases linearly. The variation of the solubility coefficient with temperature under different pressure conditions all decreases exponentially. An equation is given to calculate the solubility coefficient of methyl iodide under different pressure and temperature conditions. (authors)

Kinetic method for determination of iodide ion ultramicroamounts

International Nuclear Information System (INIS)

Barkauskas, Yu.K.; Ramanauskas, Eh.I.

1980-01-01

A kinetic method for iodides ultramicroamount determination from their catalytic effect on oxidation of malachite green with chloramine B in the presence of acetone at pH 5.78+-0.3 is developed. The induction period of the reaction is determined from a change in the redox potential of the system. The induction period is proportional to the iodides concentration. Determination limit of iodides is equal to 4 μg iodide per 100 l of solution. More than 10 5 -multiple amounts of K + , Na + , NH 4+ , Ba 2 + , Al 3 + , Cu 2 + , Mg 2 + , SO 4 2 - , Cl - , MoO 4 2 - , NO 3- , ClO 3- , IO 3- , IO 4- , ClO 4- , BrO 3- ; 10 5 -10 3 -multiple amounts of Cr 3 + , Fe 3 + , Sn 2 + , S 2 - , MnO 4- , NO 2- etc. do not interfere with the determination, while 10-multiple amounts of SCN, 0.2-multiple quantities of Ag + , Hg 2 2 + do

Products of the reaction between methylene iodide and tertiary arsines

International Nuclear Information System (INIS)

Gigauri, R.D.; Arabuli, L.G.; Machaidze, Z.I.; Rusiya, M.Sh.

2005-01-01

Iodides of iodomethylenetrialkyl(aryl) arsonium were synthesized with high yields as a result of interaction between methylene iodide and tertiary arsines. Exchange reactions of the iodides prepared with lead(II) nitrate in water-alcohol solutions gave rise to formation of iodomethylenetrialkyl(aryl) arsonium nitrates. All the products prepared were characterized by data of elementary analysis, IR spectroscopy, conductometry and melting points measurements [ru

Permeation of iodide from iodine-enriched yeast through porcine intestine.

Science.gov (United States)

Ryszka, Florian; Dolińska, Barbara; Zieliński, Michał; Chyra, Dagmara; Dobrzański, Zbigniew

2013-01-01

Iodine deficiency is a common phenomenon, threatening the whole global human population. Recommended daily intake of iodine is 150 μg for adults and 250 μg for pregnant and breastfeeding women. About 50% of human population can be at risk of moderate iodine deficiency. Due to this fact, increased iodine supplementation is recommended, through intake of iodized mineral water and salt iodization. The aim of this study was to investigate permeation and absorption of iodide from iodine bioplex (experimental group) in comparison with potassium iodide (controls). Permeation and absorption processes were investigated in vitro using a porcine intestine. The experimental model was based on a standard Franz diffusion cell (FD-Cell). The iodine bioplex was produced using Saccharomyces cerevisiae yeast and whey powder: iodine content - 388 μg/g, total protein - 28.5%, total fat - 0.9%., glutamic acid - 41.2%, asparaginic acid - 29.4%, lysine - 24.8%; purchased from: F.Z.N.P. Biochefa, Sosnowiec, Poland. Potassium iodide was used as controls, at 388 μg iodine concentration, which was the same as in iodine-enriched yeast bioplex. A statistically significant increase in iodide permeation was observed for iodine-enriched yeast bioplex in comparison with controls - potassium iodide. After 5h the total amount of permeated iodide from iodine-enriched yeast bioplex was 85%, which is ~ 2-fold higher than controls - 37%. Iodide absorption was by contrast statistically significantly higher in controls - 7.3%, in comparison with 4.5% in experimental group with iodine-enriched yeast bioplex. Presented results show that iodide permeation process dominates over absorption in case of iodine-enriched yeast bioplex.

Method of removing alkyl iodides or mixtures of iodine and alkyl iodides from a gas phase and an aqueous solution phase by utilizing ion exchange resins

International Nuclear Information System (INIS)

Shimizu, Hiroshi; Mizuuchi, Noboru; Yokoyama, Fumio.

1967-01-01

Alkyl iodides and mixtures of iodine and alkyl iodides are removed from a gas phase and an aquous solution phase by using solely an anion exchange resin containing a tertiary amine or together with an anion exchange resin containing quarternary ammonium compound. The resin containing the quarternary ammonium compound is employed mainly to remove iodine, and the resin containing the tertiary amine serves mainly to remove alkyl iodides. The method can be applied to collecting a majority of the methyl iodide as well as the radioactive iodine produced in the atmosphere of a reactor in case of a fuel accident. In embodiments, it is desirable to maintain the sufficient moisture content of the anion exchange resins at a sufficient moisture level so as not to reduce the migration speed of the iodine and alkyl iodides. The iodine and alkyl iodide can be produced with high efficiency and stability independently of the relative humidity of the gas phase. In examples, a solution which consists of 20.5 mg/l of iodine and 42.2mg/l of methyl iodide flew through a column of Amberite IRA-93 alone or blended with IRA-900 at a speed of 15 /hr. respectively. The resins were able to treat 400 times their equivalent in water. (Iwakiri, K.)

Laccase-catalyzed oxidation of iodide and formation of organically bound iodine in soils.

Science.gov (United States)

Seki, Miharu; Oikawa, Jun-ichi; Taguchi, Taro; Ohnuki, Toshihiko; Muramatsu, Yasuyuki; Sakamoto, Kazunori; Amachi, Seigo

2013-01-02

Laccase oxidizes iodide to molecular iodine or hypoiodous acid, both of which are easily incorporated into natural soil organic matter. In this study, iodide sorption and laccase activity in 2 types of Japanese soil were determined under various experimental conditions to evaluate possible involvement of this enzyme in the sorption of iodide. Batch sorption experiment using radioactive iodide tracer ((125)I(-)) revealed that the sorption was significantly inhibited by autoclaving (121 °C, 40 min), heat treatment (80 and 100 °C, 10 min), γ-irradiation (30 kGy), N(2) gas flushing, and addition of reducing agents and general laccase inhibitors (KCN and NaN(3)). Interestingly, very similar tendency of inhibition was observed in soil laccase activity, which was determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) as a substrate. The partition coefficient (K(d): mL g(-1)) for iodide and specific activity of laccase in soils (Unit g(-1)) showed significant positive correlation in both soil samples. Addition of a bacterial laccase with an iodide-oxidizing activity to the soils strongly enhanced the sorption of iodide. Furthermore, the enzyme addition partially restored iodide sorption capacity of the autoclaved soil samples. These results suggest that microbial laccase is involved in iodide sorption on soils through the oxidation of iodide.

Transmutation of americium and curium incorporated in zirconia-based host materials

Energy Technology Data Exchange (ETDEWEB)

Raison, P.E. [CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d' Etudes des Combustibles; Haire, R.G. [Oak Ridge National Lab., TN (United States)

2001-07-01

Presented are studies involving the incorporation of americium and curium in zirconia-based materials. First explored was the pseudo ternary system AmO{sub 2}-ZrO{sub 2}-Y{sub 2}O{sub 3}. It was determined that selected Y-CSZ materials can incorporate significant quantities of americium oxide and remain cubic single-phase. The cell parameters of these fluorite-type products were established to be linear with the AmO{sub 2} content. The Cm{sub 2}O{sub 3}-ZrO{sub 2} system was also investigated. It was found that at 25 mol% of CmO{sub 1.5}, the Cm(III) stabilized zirconia in its cubic form (a = 5.21 {+-}0.01 Angstrom). At higher and lower concentrations, diphasic materials were encountered. At 50 mol% of CmO{sub 1.5}, a pyrochlore oxide - Cm{sub 2}Zr{sub 2}O{sub 7} - is formed (a = 10.63 {+-}0.02 Angstrom). (author)

Colorimetric sensing of iodide based on triazole-acetamide functionalized gold nanoparticles

International Nuclear Information System (INIS)

Lee, I-Lin; Sung, Yi-Ming; Wu, Shu-Pao; Wu, Chien-Hou

2014-01-01

We have modified gold nanoparticles (AuNPs) with triazole acetamide to obtain a material for the sensitive and selective colorimetric determination of iodide. The functionalized AuNPs were prepared by a reductive single chemical step using a Cu(I)-catalyzed click reaction. The presence of iodide ions induces the aggregation of these AuNPs and results in a color change from wine-red to purple. The iodide-induced aggregation can be detected visually with bare eyes, but also by photometry. The detection limit is as low as 15 nM. The method displays excellent selectivity for iodide over other anions due to the selective interaction with the amido groups of the triazole. The method was applied to the determination of iodide in spiked lake waters. (author)

Experimental studies to validate model calculations and maximum solubility limits for Plutonium and Americium

International Nuclear Information System (INIS)

2017-01-01

This report focuses on studies of KIT-INE to derive a significantly improved description of the chemical behaviour of Americium and Plutonium in saline NaCl, MgCl 2 and CaCl 2 brine systems. The studies are based on new experimental data and aim at deriving reliable Am and Pu solubility limits for the investigated systems as well as deriving comprehensive thermodynamic model descriptions. Both aspects are of high relevance in the context of potential source term estimations for Americium and Plutonium in aqueous brine systems and related scenarios. Americium and Plutonium are long-lived alpha emitting radionuclides which due to their high radiotoxicity need to be accounted for in a reliable and traceable way. The hydrolysis of trivalent actinides and the effect of highly alkaline pH conditions on the solubility of trivalent actinides in calcium chloride rich brine solutions were investigated and a thermodynamic model derived. The solubility of Plutonium in saline brine systems was studied under reducing and non-reducing conditions and is described within a new thermodynamic model. The influence of dissolved carbonate on Americium and Plutonium solubility in MgCl 2 solutions was investigated and quantitative information on Am and Pu solubility limits in these systems derived. Thermodynamic constants and model parameter derived in this work are implemented in the Thermodynamic Reference Database THEREDA owned by BfS. According to the quality assurance approach in THEREDA, is was necessary to publish parts of this work in peer-reviewed scientific journals. The publications are focused on solubility experiments, spectroscopy of aquatic and solid species and thermodynamic data. (Neck et al., Pure Appl. Chem., Vol. 81, (2009), pp. 1555-1568., Altmaier et al., Radiochimica Acta, 97, (2009), pp. 187-192., Altmaier et al., Actinide Research Quarterly, No 2., (2011), pp. 29-32.).

Development of w/o microemulsion for transdermal delivery of iodide ions.

Science.gov (United States)

Lou, Hao; Qiu, Ni; Crill, Catherine; Helms, Richard; Almoazen, Hassan

2013-03-01

The objective of this study was to develop a water-in-oil (w/o) microemulsion which can be utilized as a transdermal delivery for iodide ions. Several w/o microemulsion formulations were prepared utilizing Span 20, ethanol, Capryol 90®, and water. The selected formulations had 5%, 10%, 15%, 20%, and a maximum of 23% w/w water content. Potassium iodide (KI) was incorporated in all formulations at 5% w/v. Physicochemical characterizations were conducted to evaluate the structure and stability. These studies included: mean droplet size, pH, viscosity, conductivity, and chemical stability tests. In vitro human skin permeation studies were conducted to evaluate the diffusion of the iodide ion through human skin. The w/o microemulsion formulations were stable and compatible with iodide ions with water content ranging from 5% to 23% w/w. The addition of KI influenced the physicochemical properties of microemulsion as compared to blank microemulsion formulations. In vitro human skin permeation studies indicated that selected formulations improved iodide ion diffusion significantly as compared to control (KI solution; P valuemicroemulsion. Span 20, ethanol and Capryol 90 protected the iodide ions against oxidation and formed a stable microemulsion. It is worth to note that according to Hofmeister series, iodide ions tend to lower the interfacial tension between water and oil and consequently enhance overall stability. This work illustrates that microemulsion system can be utilized as a vehicle for the transdermal administration of iodide.

Radiolytic formation of organic iodides from organic compounds released from ripolin paint

International Nuclear Information System (INIS)

Attia, S.; Evans, G.J.

2002-01-01

The impact of a serious nuclear reactor accident is governed to a large extent by the possible release of airborne organic iodides to the environment. This research examines the identification and behavior of organic iodides formed in the containment due to the release of organic compounds from Ripolin paint, into the aqueous phase, following a nuclear reactor accident. A bench scale apparatus installed in the irradiation chamber of a Gammacell was used to analyze the formation of organic iodides. Iodo-organics, transferred to the gas phase above irradiated aqueous samples, were analyzed using a Thermal Desorption method coupled with gas chromatography and mass spectrometry. Detailed studies of the identity of the organic compounds released and the organic iodides formed were conducted. The effects of parameters such as irradiation dose were also examined. All the organic iodides formed, under radiolytic conditions, were identified as iodo-alkanes. The organic compounds that were released from the Ripolin paint, such as methyl isobutyl ketone, were found to decompose, by a series of reactions, to produce the organic iodides. The precursor organic compounds and the organic iodides formed were observed to consist of the same alkyl group. These results indicate that organic compounds released from surface paints directly influence the formation of radiolytic organic iodide. (author)

Parametric Study on the Organic Iodide Behavior during a Severe Accident

International Nuclear Information System (INIS)

Ryu, Myung Hyun; Kim, Han Chul; Kim, Do Sam

2011-01-01

Iodine is a major contributor to the potential health risk for the public following a severe accident from a nuclear power plant. Most of metal-iodides, the major form of iodine that enters the containment, can be readily dissolved in the sump water and result in iodide ions. These will be oxidized to form volatile I 2 through a large number of reactions such as radiolysis and hydrolysis. The organic radicals, made from organics such as paint in the sump water, react with iodine to produce organic iodides. Volatile iodine moves from the sump water to the atmosphere mainly by diffusion and natural convection, and react with surfaces and air radiolysis products (ARPs). Painted surfaces act as a sink for I 2 and as a source for organic iodides through adsorption and desorption. ARPs react with I 2 to form iodine oxides, which leads to the decrease of I 2 and organic iodides. Among the large number of iodine species, organic iodides have been extensively studied recently due to their volatility and very low retention. Qualified tools for modeling these phenomena have been developed and validated by several experiments such as EPICUR, PARIS and OECD-BIP. While mechanistic codes model a large number of reactions and species, semiempirical codes such as IODE or IMOD treat major ones. KINS developed a simple iodine model, RAIM (Radio-active iodine chemistry model), based on the IMOD methodology in order to deal with organic iodides conveniently, coupling with an integrated severe-accident analysis code. There are a number of mechanisms that affect the behavior of organic iodides. In this study, effects of pH of the aqueous phase, temperature, radiation dose rate, surface area of organic paints, initial iodine loads that are known to be important to organic iodide formation were studied analytically with RAIM, and also theoretically

Parametric Study on the Organic Iodide Behavior during a Severe Accident

Energy Technology Data Exchange (ETDEWEB)

Ryu, Myung Hyun; Kim, Han Chul; Kim, Do Sam [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2011-10-15

Iodine is a major contributor to the potential health risk for the public following a severe accident from a nuclear power plant. Most of metal-iodides, the major form of iodine that enters the containment, can be readily dissolved in the sump water and result in iodide ions. These will be oxidized to form volatile I{sub 2} through a large number of reactions such as radiolysis and hydrolysis. The organic radicals, made from organics such as paint in the sump water, react with iodine to produce organic iodides. Volatile iodine moves from the sump water to the atmosphere mainly by diffusion and natural convection, and react with surfaces and air radiolysis products (ARPs). Painted surfaces act as a sink for I{sub 2} and as a source for organic iodides through adsorption and desorption. ARPs react with I{sub 2} to form iodine oxides, which leads to the decrease of I{sub 2} and organic iodides. Among the large number of iodine species, organic iodides have been extensively studied recently due to their volatility and very low retention. Qualified tools for modeling these phenomena have been developed and validated by several experiments such as EPICUR, PARIS and OECD-BIP. While mechanistic codes model a large number of reactions and species, semiempirical codes such as IODE or IMOD treat major ones. KINS developed a simple iodine model, RAIM (Radio-active iodine chemistry model), based on the IMOD methodology in order to deal with organic iodides conveniently, coupling with an integrated severe-accident analysis code. There are a number of mechanisms that affect the behavior of organic iodides. In this study, effects of pH of the aqueous phase, temperature, radiation dose rate, surface area of organic paints, initial iodine loads that are known to be important to organic iodide formation were studied analytically with RAIM, and also theoretically

Electrodeposition of americium on a liquid cadmium cathode from a molten salt bath

International Nuclear Information System (INIS)

Laplace, A.; Lacquement, J.; Maillard, C.; Donner, L.

2004-01-01

A high-activity experiment involving the electrode position of americium on a liquid cadmium cathode from a LiCl-KCl eutectic with about 3 g of AmO 2 was conducted in a shielded cell in the ATALANTE complex. After describing the electrolyzer and the experimental conditions, the authors discuss the preparation of the LiCl-KCl-AmCl 3 solution and briefly review its electrochemical properties. It was clearly confirmed that Am(III) reduction on an inert solid cathode occurs in two steps forming Am(II) before Am(0), whereas only one reduction step was observed on liquid cadmium. The main results of this study concern americium electrode position on the liquid cadmium cathode (recovery yields, current densities, problems encountered). The solvent properties of cadmium for actinide/lanthanide separation are discussed. (authors)

Plutonium and americium extraction studies with bifunctional organophosphorus extractants

International Nuclear Information System (INIS)

Navratil, J.D.

1985-01-01

Neutral bifunctional organophosphorus extractants, such as octylphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and dihexyl-N,N-diethylcarbamoylmethylphosphonate (CMP), are under study at the Rocky Flats Plant (RFP) to remove plutonium and americium from the 7M nitric acid waste. These compounds extract trivalent actinides from strong nitric acid, a property which distinguishes them from monofunctional organiphosphorus reagents. Furthermore, the reagents extract hydroytic plutonium (IV) polymer which is present in the acid waste stream. The compounds extract trivalent actinides with a 3:1 stoichiometry, whereas tetra- and hexavalent actinides extract with a stoichiometry of 2:1. Preliminary studies indicate that the extracted plutonium polymer complex contains one to two molecules of CMP per plutonium ion and the plutonium(IV) maintains a polymeric structure. Recent studies by Horwitz and co-workers conclude that the CMPO and CMP reagents behave as monodentate ligands. At RFP, three techniques are being tested for using CMP and CMPO to remove plutonium and americium from nitric acid waste streams. The different techniques are liquid-liquid extraction, extraction chromatography, and solid-supported liquid membranes. Recent tests of the last two techniques will be briefly described. In all the experiments, CMP was an 84% pure material from Bray Oil Co. and CMPO was 98% pure from M and T Chemicals

Determination of plutonium, americium and curium in the marine environment

International Nuclear Information System (INIS)

Grenaut, CLaude; Germain, Pierre; Miramand, Pierre.

1982-01-01

The method used in the Laboratory for plutonium, americium and curium determination in marine samples (water, sediments, animals, plants) is presented. It is a modification of a procedure based on adsorption on ion exchange resins developed by other authors. The preliminary preparation of the samples, the radiochemical procedures and electrodeposition are described so as to be used as a practical handbook [fr

Thyroid iodide compartments and their implication in the rat thyroid iodine organification

International Nuclear Information System (INIS)

Bastiani, P.; Simon, C.

1982-01-01

To estimate the relative participation of transported and intrathyroidally generated iodide (internal iodide) in the iodination of newly synthesized and preexisting thyroglobulin (Tg) in the rat thyroid, the specific radioactivities (SRAs) of thyroid iodide, Tg, lysosomal iodine, and plasma hormones were followed for 92 h after radioactive iodide injection in intact or hypophysectomized rats. In control rats, the SRA of Tg and lysosomal iodine reached a maximum at 12 h. However, the SRA of lysosomal iodide was always smaller than that of Tg. In contrast, the SRA of hormonal iodide attained a maximum at 48 h. Thus, newly labeled iodine is endocytosed and mixed inside the lysosomes with older previously iodinated molecules; hormone secretion is mainly due to old labeled iodine (i.e. iodine with a high SRA from 48-96 h). These results are consistent with the presence of least two Tg compartments, with different turnover rates and hormone contents. On the other hand, in hypophysectomized rats, the SRA of Tg, lysosomes, and hormones showed only one maximum, at 24 h. Furthermore, the SRAs of Tg and lysosomes were similar at each time interval. It is inferred that in such rats, the old labeled iodine compartment is strongly reduced, and that inside the lysosomes, newly labeled iodine is predominant. Since in hypophysectomized rats, the recycling of iodide is abolished, it is concluded that in normal rats: 1) transported iodide is organified mainly by direct iodination of newly synthesized Tg, independently of TSH, and 2) internal iodide is organified mainly by delayed iodination of preexisting Tg, this process being TSH dependent

Study on gold concentrate leaching by iodine-iodide

Science.gov (United States)

Wang, Hai-xia; Sun, Chun-bao; Li, Shao-ying; Fu, Ping-feng; Song, Yu-guo; Li, Liang; Xie, Wen-qing

2013-04-01

Gold extraction by iodine-iodide solution is an effective and environment-friendly method. In this study, the method using iodine-iodide for gold leaching is proved feasible through thermodynamic calculation. At the same time, experiments on flotation gold concentrates were carried out and encouraging results were obtained. Through optimizing the technological conditions, the attained high gold leaching rate is more than 85%. The optimum process conditions at 25°C are shown as follows: the initial iodine concentration is 1.0%, the iodine-to-iodide mole ratio is 1:8, the solution pH value is 7, the liquid-to-solid mass ratio is 4:1, the leaching time is 4 h, the stirring intensity is 200 r/mim, and the hydrogen peroxide consumption is 1%.

Standard free energy of formation of iron iodide

Science.gov (United States)

Khandkar, A.; Tare, V. B.; Wagner, J. B., Jr.

1983-01-01

An experiment is reported where silver iodide is used to determine the standard free energy of formation of iron iodide. By using silver iodide as a solid electrolyte, a galvanic cell, Ag/AgI/Fe-FeI2, is formulated. The standard free energy of formation of AgI is known, and hence it is possible to estimate the standard free energy of formation of FeI2 by measuring the open-circuit emf of the above cell as a function of temperature. The free standard energy of formation of FeI2 determined by this method is -38784 + 24.165T cal/mol. It is estimated that the maximum error associated with this method is plus or minus 2500 cal/mol.

1976 Hanford americium-exposure incident: decontamination and treatment facility

International Nuclear Information System (INIS)

Berry, J.R.; McMurray, B.J.; Jech, J.J.; Breitenstein, B.D.; Quigley, E.J.

1982-01-01

An injured worker, contaminated with over 6 mCi of americium-241, required special treatment and housing for 4 months. This paper is a description of the design and management of the facility in which most of the treatment and housing occurred. The problems associated with contamination control, waste handling, supplies, and radiological concerns during the two-stage transfer of the patient from a controlled situation to his normal living environment are discussed in detail

The transmutation of americium: the Ecrix experiments in Phenix; Transmutation de l'americium: les experiences ecrix dans Phenix

Energy Technology Data Exchange (ETDEWEB)

Garnier, J C; Schmidt, N [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC/SESC), 13 - Saint-Paul-lez-Durance (France); Croixmarie, Y; Ottaviani, J P [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC/SPUA), 13 - Saint-Paul-lez-Durance (France); Varaine, F; Saint Jean, C de [CEA Cadarache, Dept. d' Etudes des Reacteurs (DER/SPRC), 13 - Saint-Paul-lez-Durance (France)

1999-07-01

The first americium transmutation experiment in a specific target in PHENIX will occur with the ECRIX-B and ECRIX-H experiments. Beside material testing, the objective is also to represent a concept of transmutation whose specificity is to enhance the kinetics of transmutation by using a moderated spectrum. The moderator materials will be {sup 11}B{sub 4}C and CaH{sub 2} for ECRIX-B and ECRIXH respectively, the irradiation conditions have been predicted for both the neutronics and thermal. The targets (MgO-AmO{sub X} pellets) are manufactured in the ATALANTE laboratory and the design is performed according to the PHENIX operating conditions. (authors)

Behavior of radioactive organic iodide in an atmosphere of High Temperature Gas-cooled Reactor

International Nuclear Information System (INIS)

Saeki, Masakatsu; Nakashima, Mikio; Sagawa, Chiaki; Masaki, Nobuyuki; Hirabayashi, Takakuni; Aratono, Yasuyuki

1990-06-01

Formation and decomposition behavior of radioactive organic iodide have been studied in an atmosphere of High Temperature Gas-cooled Reactor (High Temperature Engineering Test Reactor, HTTR). Na 125 I was chosen for radioactive iodine source instead of CsI diffusing from coated fuel particles. Na 125 I adsorbed on graphite was heated in pure He and He containing O 2 or H 2 O atmosphere. The results obtained are as follows. It was proved that organic iodide was formed with organic radicals released from graphite even in He atmosphere. Thus, the interchange rate of inorganic iodide with organic iodide was remarkably decreased with prolonged preheat-treatment period at 1000degC. Organic iodide formed was easily decomposed by its recirculation into hot reaction tube kept at 900degC. When organic iodide was passed through powdered graphite bed, more than 70% was decomposed at 90degC. Oxygen and water vapour intermixed in He suppressed the interchange rate of inorganic iodide with organic iodide. These results suggest that organic iodide rarely exists in the pressure vessel under normal operating condition of HTTR, and, under hypothetical accident condition of HTTR, organic iodide fraction never exceeds the value used for a safety assessment of light water reactor. (author)

Uptake and recovery of americium and uranium by Anacystis biomass

International Nuclear Information System (INIS)

Liu, H.H.; Jiunntzong Wu

1993-01-01

The optimum conditions for the uptake of americium and uranium from wastewater solutions by Anacystis nidulans cells, and the recovery of these radionuclides were studied. The optimum pH range for both actinides was in the acidic region between 3.0 and 5.0. In a pH 3.5 solution with an algal biomass of 70 μg/mL, up to 95% of the Am and U were taken up by the cells. However, the uptake levels were lowered considerably when ethylene dinitrilotetraacetic acid (EDTA) or iron or calcium ions were present in the solutions. Most of the radionuclides taken up by the cells could also be desorbed by washing with salt solutions. Of nine salt solutions tested, ammonium carbonate was the most effective. Our experiments using algal biomass to remove radionuclides from wastewater showed that about 92% of americium and 85% of uranium in wastewater could be taken up by algal biomass, from which about 46% of the Am and 82% of the U originally present in the wastewater could be recovered by elution with a salt solution. 17 refs., 7 figs., 2 tabs

Picomolar traces of americium(III) introduce drastic changes in the structural chemistry of terbium(III). A break in the ''gadolinium break''

Energy Technology Data Exchange (ETDEWEB)

Welch, Jan M. [TU Wien, Atominstitut, Vienna (Austria); Mueller, Danny; Knoll, Christian; Wilkovitsch, Martin; Weinberger, Peter [TU Wien, Institute of Applied Synthetic Chemistry, Vienna (Austria); Giester, Gerald [University of Vienna, Institute of Mineralogy and Crystallography, Vienna (Austria); Ofner, Johannes; Lendl, Bernhard [TU Wien, Institute of Chemical Technologies and Analytics, Vienna (Austria); Steinhauser, Georg [Leibniz Universitaet Hannover, Institute of Radioecology and Radiation Protection (Germany)

2017-10-16

The crystallization of terbium 5,5{sup '}-azobis[1H-tetrazol-1-ide] (ZT) in the presence of trace amounts (ca. 50 Bq, ca. 1.6 pmol) of americium results in 1) the accumulation of the americium tracer in the crystalline solid and 2) a material that adopts a different crystal structure to that formed in the absence of americium. Americium-doped [Tb(Am)(H{sub 2}O){sub 7}ZT]{sub 2} ZT.10 H{sub 2}O is isostructural to light lanthanide (Ce-Gd) 5,5{sup '}-azobis[1H-tetrazol-1-ide] compounds, rather than to the heavy lanthanide (Tb-Lu) 5,5{sup '}-azobis[1H-tetrazol-1-ide] (e.g., [Tb(H{sub 2}O){sub 8}]{sub 2}ZT{sub 3}.6 H{sub 2}O) derivatives. Traces of Am seem to force the Tb compound into a structure normally preferred by the lighter lanthanides, despite a 10{sup 8}-fold Tb excess. The americium-doped material was studied by single-crystal X-ray diffraction, vibrational spectroscopy, radiochemical neutron activation analysis, and scanning electron microscopy. In addition, the inclusion properties of terbium 5,5{sup '}-azobis[1H-tetrazol-1-ide] towards americium were quantified, and a model for the crystallization process is proposed. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

A simple approach to determine the diffusivity of americium in granite

International Nuclear Information System (INIS)

Song, L.; Feng, X.; Liang, J.; Zhang, Y.; Wang, J.

2009-01-01

The diffusivities of the key radionuclides in host rock are important for the performance assessment of repositories. One of the conventional methods for determining the diffusivities of radionuclides is to grind the rock tablet layer by layer and then to measure the radioactivity remaining on the rock tablet before each grinding cycle. Since grinding hard rock samples, especially those with radioactivity, is very difficult, we developed a new approach to determine the diffusivity of americium in granite. The new approach mainly includes two parts: one is to measure the radioactivities from both sides of a rock disk sample by autoradiography with phosphor imaging technique; the other is to study the relationship between the radioactivities and the apparent diffusivity of americium in granite by computer modelling. Because the high contamination risk of grinding radioactive rock samples has been avoided, the new approach is much simpler than the conventional method. It may be a better choice of measuring the diffusivities of radionuclides in rock, especially for those laboratories in which grinding radioactive rock samples is inconvenient. (orig.)

Standard test method for quantitative determination of americium 241 in plutonium by Gamma-Ray spectrometry

CERN Document Server

American Society for Testing and Materials. Philadelphia

1994-01-01

1.1 This test method covers the quantitative determination of americium 241 by gamma-ray spectrometry in plutonium nitrate solution samples that do not contain significant amounts of radioactive fission products or other high specific activity gamma-ray emitters. 1.2 This test method can be used to determine the americium 241 in samples of plutonium metal, oxide and other solid forms, when the solid is appropriately sampled and dissolved. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Influence of dissolved organic substances in groundwater on sorption behavior of americium and neptunium

International Nuclear Information System (INIS)

Boggs, S. Jr.; Seitz, M.G.

1984-01-01

Groundwaters typically contain dissolved organic carbon consisting largely of high molecular weight compounds of humic and fulvic acids. To evaluate whether these dissolved organic substances can enhance the tranport of radionuclides through the groundwater system, experiments were conducted to examine the sorption of americium and neptunium onto crushed basalt in the presence of dissolved humic- and fulvic-acid organic carbon introduced into synthetic groundwater. The partitioning experiments with synthetic groundwater show that increasing the concentration of either humic or fulvic acid in the water has a significant inhibiting effect on sorption of both americium and neptunium. At 22 0 C, adsorption of these radionuclides, as measured by distribution ratios (the ratio of nuclide sorbed onto the solid to nuclide in solution at the end of the experiment), decreased by 25% to 50% by addition of as little as 1 mg/L dissolved organic carbon and by one to two orders of magnitude by addition of 100 to 200 mg/L dissolved organic carbon. Distribution ratios measured in solutions reacted at 90 0 C similarly decreased with the addition of dissolved organic carbon but generally ranged from one to two orders of magnitude higher than those determined in the 22 0 C experiment. These results suggest that organic carbon dissolved in deep groundwaters may significantly enhance the mobility of radionuclides of americium and neptunium. 23 references, 5 figures, 11 tables

Recovery of americium-241 from aged plutonium metal

International Nuclear Information System (INIS)

Gray, L.W.; Burney, G.A.; Reilly, T.A.; Wilson, T.W.; McKibben, J.M.

1980-01-01

After separation and purification, both actinides were precipitated as oxalates and calcined. A large-scale process was developed using dissolution, separation, purification, precipitation, and calcination. Efforts were made to control corrosion, to avoid product contamination, to keep the volume of process and waste solutions manageable, and to denitrate solutions with formic acid. The Multipurpose Processing Facility (MPPF), designed for recovery of transplutonium isotopes, was used for the first time for the precipitation and calcination of americium. Also, for the first time,, large-scale formic acid denitration was performed in a canyon vessel at SRP

Determination of nanogram amounts of iodide by electrochemical isotope dilution analysis

International Nuclear Information System (INIS)

Gabrielsson, A.-B.; Beronius, P.

1976-01-01

A known quantity of iodide in ethanol as solvent was labelled with 131 I-and subsequently diluted with a predetermined amount of inactive iodide. Specific activities before and after the isotope dilution were established by anodically depositing small fractions of the halide in each sample on rotating silver micro electrodes and determining the activities of the electrodeposits. The lowest concentration of iodide used in any analysis was 1.10 -5 M. Further deposition studies revealed that iodide can be deposited with 1 100% current efficiency on the rotating silver micro electrode for concentration down to 2.4.10 -6 M. Electrodeposition studies for still lower concentrations have not yet been undertaken. These results suggest that amounts of iodide ion down to about 10 ng, and possibly still smaller quantitites, might be determined with the method developed. Amounts from 42 ng to 1 μg can be determined with an error of 2.5%. (T.G.)

Upper limits to americium concentration in large sized sodium-cooled fast reactors loaded with metallic fuel

International Nuclear Information System (INIS)

Zhang, Youpeng; Wallenius, Janne

2014-01-01

Highlights: • The americium transmutation capability of Integral Fast Reactor was investigated. • The impact from americium introduction was parameterized by applying SERPENT Monte Carlo calculations. • Higher americium content in metallic fuel leads to a power penalty, preserving consistent safety margins. - Abstract: Transient analysis of a large sized sodium-cooled reactor loaded with metallic fuel modified by different fractions of americium have been performed. Unprotected loss-of-offsite power, unprotected loss-of-flow and unprotected transient-over-power accidents were simulated with the SAS4A/SASSYS code based on the geometrical model of an IFR with power rating of 2500 MW th , using safety parameters obtained with the SERPENT Monte Carlo code. The Ti-modified austenitic D9 steel, having higher creep rupture strength, was considered as the cladding and structural material apart from the ferritic/martensitic HT9 steel. For the reference case of U–12Pu–1Am–10Zr fuel at EOEC, the margin to fuel melt during a design basis condition UTOP is about 50 K for a maximum linear rating of 30 kW/m. In order to maintain a margin of 50 K to fuel failure, the linear power rating has to be reduced by ∼3% and 6% for 2 wt.% and 3 wt.% Am introduction into the fuel respectively. Hence, an Am concentration of 2–3 wt.% in the fuel would lead to a power penalty of 3–6%, permitting a consumption rate of 3.0–5.1 kg Am/TW h th . This consumption rate is significantly higher than the one previously obtained for oxide fuelled SFRs

Method to remove methyl iodide131 gas

International Nuclear Information System (INIS)

Deitz, V.R.; Blachly, C.H.

1977-01-01

A two-stage impregnation process for charcoal is presented which is to be used for radioactive iodine or methyl iodide removal from the waste gas of a nuclear reactor. In the first stage, the coal is treated at pH 10 with an aqueous mixture of a salt of iodic acid (hypoiodite, iodate, or periodate) with iodine or iodide. In the second stage, impregnation with a tertiary amine occurs. The concentrations are chosen so that the charcoal will take up between 0.5 and 4% by weight of iodine. (UWI) [de

The transmutation of americium: the Ecrix experiments in Phenix; Transmutation de l'americium: les experiences ecrix dans Phenix

Energy Technology Data Exchange (ETDEWEB)

Garnier, J.C.; Schmidt, N. [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC/SESC), 13 - Saint-Paul-lez-Durance (France); Croixmarie, Y.; Ottaviani, J.P. [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC/SPUA), 13 - Saint-Paul-lez-Durance (France); Varaine, F.; Saint Jean, C. de [CEA Cadarache, Dept. d' Etudes des Reacteurs (DER/SPRC), 13 - Saint-Paul-lez-Durance (France)

1999-07-01

The first americium transmutation experiment in a specific target in PHENIX will occur with the ECRIX-B and ECRIX-H experiments. Beside material testing, the objective is also to represent a concept of transmutation whose specificity is to enhance the kinetics of transmutation by using a moderated spectrum. The moderator materials will be {sup 11}B{sub 4}C and CaH{sub 2} for ECRIX-B and ECRIXH respectively, the irradiation conditions have been predicted for both the neutronics and thermal. The targets (MgO-AmO{sub X} pellets) are manufactured in the ATALANTE laboratory and the design is performed according to the PHENIX operating conditions. (authors)

A glucose bio-battery prototype based on a GDH/poly(methylene blue) bioanode and a graphite cathode with an iodide/tri-iodide redox couple.

Science.gov (United States)

Wang, Jen-Yuan; Nien, Po-Chin; Chen, Chien-Hsiao; Chen, Lin-Chi; Ho, Kuo-Chuan

2012-07-01

A glucose bio-battery prototype independent of oxygen is proposed based on a glucose dehydrogenase (GDH) bioanode and a graphite cathode with an iodide/tri-iodide redox couple. At the bioanode, a NADH electrocatalyst, poly(methylene blue) (PMB), which can be easily grown on the electrode (screen-printed carbon paste electrode, SPCE) by electrodeposition, is harnessed and engineered. We find that carboxylated multi-walled carbon nanotubes (MWCNTs) are capable of significantly increasing the deposition amount of PMB and thus enhancing the PMB's electrocatalysis of NADH oxidation and the glucose bio-battery's performance. The choice of the iodide/tri-iodide redox couple eliminates the dependence of oxygen for this bio-battery, thus enabling the bio-battery with a constant current-output feature similar to that of the solar cells. The present glucose bio-battery prototype can attain a maximum power density of 2.4 μW/cm(2) at 25 °C. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Co-precipitation of plutonium(IV) and americium(III) from nitric acid-oxalic acid solutions with bismuth oxalate

International Nuclear Information System (INIS)

Pius, I.C.; Noronha, D.M.; Chaudhury, Satyajeet

2017-01-01

Co-precipitation of plutonium and americium from nitric acid-oxalic acid solutions with bismuth oxalate has been investigated for the removal of these long lived α-active nuclides from waste solutions. Effect of concentration of bismuth and oxalic acid on the co-precipitation of Pu(IV) from 3 M HNO_3 has been investigated. Similar experiments were also carried out from 3.75 M HNO_3 on co-precipitation of Am(III) to optimize the conditions of precipitation. Strong co-precipitation of Pu(IV) and Am(III) with bismuth oxalate indicate feasibility of treatment of plutonium and americium bearing waste solutions. (author)

The iodine/iodide redox couple at a platinum electrode

NARCIS (Netherlands)

Dane, L.M.; Janssen, L.J.J.; Hoogland, J.G.

1968-01-01

The I/iodide redox couple was studied on Pt in 0.5M H2SO4 by measuring the impedance as a function of frequency. From these measurements, the exchange c.d. j0 was derived according to Sluyters. The dependence of j0 on the reversible potential and the I and the iodide concns. was established. By

Auger recombination in sodium iodide

Science.gov (United States)

McAllister, Andrew; Kioupakis, Emmanouil; Åberg, Daniel; Schleife, André

2014-03-01

Scintillators are an important tool used to detect high energy radiation - both in the interest of national security and in medicine. However, scintillator detectors currently suffer from lower energy resolutions than expected from basic counting statistics. This has been attributed to non-proportional light yield compared to incoming radiation, but the specific mechanism for this non-proportionality has not been identified. Auger recombination is a non-radiative process that could be contributing to the non-proportionality of scintillating materials. Auger recombination comes in two types - direct and phonon-assisted. We have used first-principles calculations to study Auger recombination in sodium iodide, a well characterized scintillating material. Our findings indicate that phonon-assisted Auger recombination is stronger in sodium iodide than direct Auger recombination. Computational resources provided by LLNL and NERSC. Funding provided by NA-22.

Radiochemical separation and alpha-spectrometric determination of Americium in different matrixes

International Nuclear Information System (INIS)

Radenkovic, M.; Joksic, J.; Paligoric, D.

2009-01-01

A method of separation and alpha-spectrometric determination of americium, developed in VINCA Institute of Nuclear Sciences is described in the paper. The procedure is convenient to be used for 241 Am determination in environmental matrixes as well as samples of human origin if a very small concentrations are expected, using 243 Am as a tracer for radiochemical yield recovery. (author) [sr

A selective iodide ion sensor electrode based on functionalized ZnO nanotubes.

Science.gov (United States)

Ibupoto, Zafar Hussain; Khun, Kimleang; Willander, Magnus

2013-02-04

In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF) was measured by the potentiometric method. The iodide ion sensor exhibited a linear response over a wide range of concentrations (1 × 10-6 to 1 × 10-1 M) and excellent sensitivity of -62 ± 1 mV/decade. The detection limit of the proposed sensor was found to be 5 × 10-7 M. The effects of pH, temperature, additive, plasticizer and stabilizer on the potential response of iodide ion selective electrode were also studied. The proposed iodide ion sensor demonstrated a fast response time of less than 5 s and high selectivity against common organic and the inorganic anions. All the obtained results revealed that the iodide ion sensor based on functionalized ZnO nanotubes may be used for the detection of iodide ion in environmental water samples, pharmaceutical products and other real samples.

A Selective Iodide Ion Sensor Electrode Based on Functionalized ZnO Nanotubes

Directory of Open Access Journals (Sweden)

Magnus Willander

2013-02-01

Full Text Available In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF was measured by the potentiometric method. The iodide ion sensor exhibited a linear response over a wide range of concentrations (1 × 10−6 to 1 × 10−1 M and excellent sensitivity of –62 ± 1 mV/decade. The detection limit of the proposed sensor was found to be 5 × 10−7 M. The effects of pH, temperature, additive, plasticizer and stabilizer on the potential response of iodide ion selective electrode were also studied. The proposed iodide ion sensor demonstrated a fast response time of less than 5 s and high selectivity against common organic and the inorganic anions. All the obtained results revealed that the iodide ion sensor based on functionalized ZnO nanotubes may be used for the detection of iodide ion in environmental water samples, pharmaceutical products and other real samples.

Adsorption-Desorption Characteristics of Plutonium and Americium with Sediment Particles in the Estuarine Environment

International Nuclear Information System (INIS)

Murray, C.N.; Fukai, R.

1976-01-01

The particle formation of plutonium and americium, their adsorption onto fresh water sediments and the desorption from the sediments in sea water were studied in the Laboratory under simulated river-estuary conditions, using γ-emitting plutonium-237 and americium-241. The results of the experiments show that the particle formation of plutonium depends on its valence states, on pH and on the salinity of the medium. For river water at pH4, some 25%, 20% and 30% of the added 237 Pu was in particulate form, larger than 0.45pm, for Pu (III), Pu (IV) and Pu (VI), respectively, while 65%, 90% and 50% of the respective valence states was associated with particles at pH 8. In sea water the general pattern remains similar, although Pu (VI) is more soluble in sea water owing to higher ligand concentrations for carbonate and bicarbonate complexes. The pH-dependency of particle formation of Am (III) is more steep than that of plutonium and seems to be influenced by colloidal substances occurring in the experimental media. The adsorption-desorption characteristics of plutonium and americium with the sediment in river water as well as sea water reflect the characteristics of their particle formation, being dependent upon such properties as valence states, the pH and salinity of the medium. A sewage effluent added to the media has small but measurable effects on the adsorption-desorption processes of plutonium. (author)

The iodide sym-porter (NIS): new perspectives in nuclear oncology

International Nuclear Information System (INIS)

Pourcher, Th.; Lindenthal, S.; Basquin, C.; Ferhat, O.; Marsault, R.; Carrier, P.; Koulibaly, M.; Bussiere, F.; Darcourt, J.

2005-01-01

The sodium iodide sym-porter (NIS) is the plasma membrane protein that mediates uptake of iodide in the thyroid and other organs such as the stomach and the salivary gland. The cloning of its cDNA allows the targeting of NIS expression into any cell using gene therapy. This enables iodide uptake and thus NIS can be used as reporter imaging for live animals. More intriguingly, this new technique has potential using radio-iodide therapy to selectively destroy tumour cells. These two approaches employ common techniques in nuclear medicine. Many experiments on cultured cells and on animals have been carried out; they established clearly the advantages of this genetically targeted radiotherapy. Recent studies employing this therapy on multiple myeloma cell lines implanted in mice or on hepato-carcinoma-bearing rats, resulted in important tumour remission. However, additional studies on NIS regulation and the use of alternative radioisotopes transported by NIS are required to further develop this promising approach. (author)

Americium-241: the most useful isotope of the actinide elements

International Nuclear Information System (INIS)

Navratil, J.D.

1984-01-01

Used extensively in nuclear gauges and in many other areas, this man-made element (Atomic Number 95) was first isolated in weighable amounts during World War II. Americium is now a very useful by-product of the nuclear industry and is produced in kilogram amounts by appropriate recovery, separation and purification processes. A review will be presented of its discovery, nuclear and chemical properties, and uses, with emphasis on its production process and separations chemistry

Study of the extraction and the purification of americium and trivalent actinides contained in effluents with supported liquid membranes

International Nuclear Information System (INIS)

Guillou, P.

1990-12-01

The supported liquid membrane technique is studied and developed for americium recovery from uranium or plutonium matrices and decontamination of liquid radioactive wastes. First tests on uranium-nickel solutions with a flat membrane showed the easiness of the operation and the efficiency of the process. Acid-resistant (10 N), interchangeable elements with hollow fibers, are developed and also a computerized automatic device. The different tests on americium solutions demonstrate the feasibility and the reliability of the system. Influence of various parameters on transfer kinetics is investigated

Physics of plutonium and americium recycling in PWR using advanced fuel concepts

International Nuclear Information System (INIS)

Hourcade, E.

2004-01-01

PWR waste inventory management is considered in many countries including Frances as one of the main current issues. Pu and Am are the 2 main contents both in term of volume and long term radio-toxicity. Waiting for the Generation IV systems implementation (2035-2050), one of the mid-term solutions for their transmutation involves the use of advanced fuels in Pressurized Water Reactors (PWR). These have to require as little modification as possible of the core internals, the cooling system and fuel cycle facilities (fabrication and reprocessing). The first part of this paper deals with some neutronic characteristics of Pu and/or Am recycling. In a second part, 2 technical solutions MOX-HMR and APA-DUPLEX-84 are presented and the third part is devoted to the study of a few global strategies. The main neutronic parameters to be considered for Pu and Am recycling in PWR are void coefficient, Doppler coefficient, fraction of delayed neutrons and power distribution (especially for heterogeneous configurations). The modification of the moderation ratio, the opportunity to use inert matrices (targets), the optimisation of Uranium, Plutonium and Americium contents are the key parameters to play with. One of the solutions (APA-DUPLEX-84) presented here is a heterogeneous assembly with regular moderation ratio composed with both target fuel rods (Pu and Am embedded in an inert matrix) and standard UO 2 fuel rods. An EPR (European Pressurised Reactor) type reactor, loaded only with assemblies containing 84 peripheral targets, can reach an Americium consumption rate of (4.4; 23 kg/TWh) depending on the assembly concept. For Pu and Am inventories stabilisation, the theoretical fraction of reactors loaded with Pu + Am or Pu assemblies is about 60%. For Americium inventory stabilisation, the fraction decreases down to 16%, but Pu is produced at a rate of 18.5 Kg/TWh (-25% compared to one through UOX cycle)

Evaluating iodide recycling inhibition as a novel molecular initiating event for thyroid axis disruption

Science.gov (United States)

The enzyme iodotyrosine deiodinase (dehalogenase, IYD) catalyzes iodide recycling and promotes iodide retention in thyroid follicular cells. Loss of function or chemical inhibition of IYD reduces available iodide for thyroid hormone synthesis, which leads to hormone insufficiency...

Efficient photoreductive decomposition of N-nitrosodimethylamine by UV/iodide process

International Nuclear Information System (INIS)

Sun, Zhuyu; Zhang, Chaojie; Zhao, Xiaoyun; Chen, Jing; Zhou, Qi

2017-01-01

Highlights: • N-nitrosodimethylamine (NDMA) was effectively decomposed by UV/iodide process. • NDMA was completely converted to nontoxic end products by UV/iodide process. • The photoreductive process was mainly attributed to the attack of hydrated electrons on the photoexcited NDMA. • The elimination of toxic intermediates was greatly enhanced as pH increased, but its effect on NDMA removal was negligible. - Abstract: N-nitrosodimethylamine (NDMA) has aroused extensive concern as a disinfection byproduct due to its high toxicity and elevated concentration levels in water sources. This study investigates the photoreductive decomposition of NDMA by UV/iodide process. The results showed that this process is an effective strategy for the treatment of NDMA with 99.2% NDMA removed within 10 min. The depletion of NDMA by UV/iodide process obeyed pseudo-first-order kinetics with a rate constant (k_1) of 0.60 ± 0.03 min"−"1. Hydrated electrons (e_a_q"−) generated by the UV irradiation of iodide were proven to play a critical role. Dimethylamine (DMA) and nitrite (NO_2"−) were formed as the main intermediate products, which completely converted to formate (HCOO"−), ammonium (NH_4"+) and nitrogen (N_2). Therefore, not only the high efficiencies in NDMA destruction, but the elimination of toxic intermediates make UV/iodide process advantageous. A photoreduction mechanism was proposed: NDMA initially absorbed photons to a photoexcited state, and underwent a cleavage of N−NO bond under the attack of e_a_q"−. The solution pH had little impact on NDMA removal. However, alkaline conditions were more favorable for the elimination of DMA and NO_2"−, thus effectively reducing the secondary pollution.

Electro regeneration of iodide loaded resin. Contributed Paper RD-18

International Nuclear Information System (INIS)

Kumar, Ratnesh; Kumar, T.; Sree Kumar, B.; Seshadri, K.S.; Paul, Biplob

2014-01-01

Spent resins generated in the nuclear reactor contain essentially cationic activities due to Cesium, Strontium, Cobalt, and anionic activities due to Iodide, Iodate etc with activity loading to the extent of 0.1 Cim -3 and a surface dose of the order of 5 R. It is necessary to convert the spent resin into innocuous, reusable forms. An attempt has been made to regenerate Iodide containing spent resin into OH - electrolytically by using the OH - produced at the cathode compartment of an electrolytic cell. Results show that the regeneration of the spent resin containing Iodide could be completely accomplished electrolytically more efficiently than by addition of alkali. (author)

Estradiol decreases iodide uptake by rat thyroid follicular FRTL-5 cells

Directory of Open Access Journals (Sweden)

Furlanetto T.W.

2001-01-01

Full Text Available Estradiol has well-known indirect effects on the thyroid. A direct effect of estradiol on thyroid follicular cells, increasing cell growth and reducing the expression of the sodium-iodide symporter gene, has been recently reported. The aim of the present investigation was to study the effect of estradiol on iodide uptake by thyroid follicular cells, using FRTL-5 cells as a model. Estradiol decreased basal iodide uptake by FRTL-5 cells from control levels of 2.490 ± 0.370 to 2.085 ± 0.364 pmol I-/µg DNA at 1 ng/ml (P<0.02, to 1.970 ± 0.302 pmol I-/µg DNA at 10 ng/ml (P<0.003, and to 2.038 ± 0.389 pmol I-/µg DNA at 100 ng/ml (P<0.02. In addition, 4 ng/ml estradiol decreased iodide uptake induced by 0.02 mIU/ml thyrotropin from 8.678 ± 0.408 to 7.312 ± 0.506 pmol I-/µg DNA (P<0.02. A decrease in iodide uptake by thyroid cells caused by estradiol has not been described previously and may have a role in goiter pathogenesis.

Removal efficiency of radioactive methyl iodide on TEDA-impregnated activated carbons

International Nuclear Information System (INIS)

Gonzalez-Garcia, C.M.; Gonzalez, J.F.; Roman, S.

2011-01-01

Activated carbons were prepared by different series of carbon dioxide and steam activation from walnut shells for their optimal use as radioactive methyl iodide adsorbents in Nuclear Plants. The knowledge of the most favourable textural characteristics of the activated carbons was possible by the previous study of the commercial activated carbon currently used for this purpose. In order to increase their methyl iodide affinity, the effect of triethylenediamine impregnation was studied at 5 and 10 wt.%. The results obtained indicated that in both cases the adsorption efficiency is markedly improved by the addition of impregnant, which allows the adsorbate uptake to occur not only by physical adsorption, via non-specific interactions (as in non-impregnated carbons) but also by the specific interaction of triethylenediamine with radioactive methyl iodide. Methyl iodide retention efficiencies up to 98.1% were achieved. (author)

Transfer of environmental plutonium and americium across the human gut

International Nuclear Information System (INIS)

Hunt, G.J.; Leonard, D.R.P.; Lovett, M.B.

1989-01-01

Following the ingestion of winkles obtained from a coastal area near Sellafield nuclear reprocessing plant, a group of volunteers provided urine for the next 7 days to be analysed for plutonium and americium. From this, estimates of the intake and gut transfer factors for these isotopes were determined. Preliminary estimates of gut transfer factors from a previous study by the same authors were then re-interpreted and combined with the results from the present study. (UK)

Total and Compound Formation Cross Sections for Americium Nuclei: Recommendations for Coupled-Channels Calculations

Energy Technology Data Exchange (ETDEWEB)

Escher, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-04-11

Calculations for total cross sections and compound-nucleus (CN) formation cross sections for americium isotopes are described, for use in the 2017 NA-22 evaluation effort. The code ECIS 2006 was used in conjunction with Frank Dietrich's wrapper `runtemplate'.

Efficient photoreductive decomposition of N-nitrosodimethylamine by UV/iodide process

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhuyu; Zhang, Chaojie, E-mail: myrazh@tongji.edu.cn; Zhao, Xiaoyun; Chen, Jing; Zhou, Qi

2017-05-05

Highlights: • N-nitrosodimethylamine (NDMA) was effectively decomposed by UV/iodide process. • NDMA was completely converted to nontoxic end products by UV/iodide process. • The photoreductive process was mainly attributed to the attack of hydrated electrons on the photoexcited NDMA. • The elimination of toxic intermediates was greatly enhanced as pH increased, but its effect on NDMA removal was negligible. - Abstract: N-nitrosodimethylamine (NDMA) has aroused extensive concern as a disinfection byproduct due to its high toxicity and elevated concentration levels in water sources. This study investigates the photoreductive decomposition of NDMA by UV/iodide process. The results showed that this process is an effective strategy for the treatment of NDMA with 99.2% NDMA removed within 10 min. The depletion of NDMA by UV/iodide process obeyed pseudo-first-order kinetics with a rate constant (k{sub 1}) of 0.60 ± 0.03 min{sup −1}. Hydrated electrons (e{sub aq}{sup −}) generated by the UV irradiation of iodide were proven to play a critical role. Dimethylamine (DMA) and nitrite (NO{sub 2}{sup −}) were formed as the main intermediate products, which completely converted to formate (HCOO{sup −}), ammonium (NH{sub 4}{sup +}) and nitrogen (N{sub 2}). Therefore, not only the high efficiencies in NDMA destruction, but the elimination of toxic intermediates make UV/iodide process advantageous. A photoreduction mechanism was proposed: NDMA initially absorbed photons to a photoexcited state, and underwent a cleavage of N−NO bond under the attack of e{sub aq}{sup −}. The solution pH had little impact on NDMA removal. However, alkaline conditions were more favorable for the elimination of DMA and NO{sub 2}{sup −}, thus effectively reducing the secondary pollution.

Mycoremediation. The study of transfer factor for plutonium and americium uptake from the ground

International Nuclear Information System (INIS)

Dusan Galanda; Lubomir Matel; Jana Strisovska; Silvia Dulanska

2014-01-01

In our scientific research we have monitored mycoremediation's properties of oyster mushrooms in cultivation on the soil what is contaminated by solutions with radioactive isotopes of 239 Pu and 241 Am with known activity. We monitored specific activities of absorbed radionuclides in fruiting bodies and chemical forms of radionuclides which were compared to calculated specific activities of two background samples of oyster mushrooms intended for consumer purpose. We determined distributive coefficients between the ground and the fruiting body of oyster mushrooms. The average value which was obtained for the transfer factor for plutonium was 0.72 and for americium 3.97. To evaluate a quantity of absorbed radionuclides we used a method of liquid extraction. The emitting alpha radiation of alpha radionuclides was detected by spectrometry. For defining individual fractions of plutonium and americium that are contained in mushroom bodies was used the sequential leaching method. (author)

High-purity germanium detection system for the in vivo measurement of americium and plutonium

International Nuclear Information System (INIS)

Tyree, W.H.; Falk, R.B.; Wood, C.B.; Liskey, R.W.

1976-01-01

A high-purity germanium (HPGe) array, photon-counting system has been developed for the Rocky Flats Plant Body-Counter Medical Facility. The newly improved system provides exceptional resolutions of low-energy X-ray and gamma-ray spectra associated with the in vivo deposition of plutonium and americium. Described are the operational parameters of the system and some qualitative results illustrating detector performance for the photon emissions produced from the decay of plutonium and americium between energy ranges from 10 to 100 kiloelectron volts. Since large amounts of data are easily generated with the system, data storage, analysis, and computer software developments continue to be an essential ingredient for processing spectral data obtained from the detectors. Absence of quantitative data is intentional. The primary concern of the study was to evaluate the effects of the various physical and electronic operational parameters before adding those related entirely to a human subject

Oxygen-hydrogen fuel cell with an iodine-iodide cathode - A concept

Science.gov (United States)

Javet, P.

1970-01-01

Fuel cell uses a porous cathode through which is fed a solution of iodine in aqueous iodide solution, the anode is a hydrogen electrode. No activation polarization appears on the cathode because of the high exchange-current density of the iodine-iodide electrode.

Adsorption of methyl iodide on charcoal

International Nuclear Information System (INIS)

Hidajat, K.; Aracil, J.; Kenney, C.N.

1990-01-01

The adsorption of non-radioactive methyl iodide has been measured experimentally over a range of conditions of concentration, and temperature on an activated charcoal. This is of interest since methyl iodide is formed from iodine fission products in gas cooled nuclear reactors. A mathematical model has also been developed which describes the rate of adsorption, under isothermal and linear adsorption isotherm conditions in a recycle adsorber. This model takes into account the resistance to adsorption caused by the surface adsorption, as well as the external and internal mass transfer resistances. The solution to the model for the recycle adsorber was obtained using a semidiscretisation method to reduce the partial differential equations to a system of stiff ordinary differential equations, and the resulting differential equations solved by a standard numerical technique. (author)

FY-2015 Methyl Iodide Deep-Bed Adsorption Test Report

International Nuclear Information System (INIS)

Soelberg, Nicholas Ray; Watson, Tony Leroy

2015-01-01

Nuclear fission produces fission and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2015 according to a multi-laboratory methyl iodide adsorption test plan. Updates to the deep-bed test system have also been performed to enable the inclusion of evaporated HNO 3 and increased NO 2 concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced silver zeolite (AgZ) resulted in initial iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) under 1,000 for the conditions of the long-duration test performed this year (45 ppm CH3I, 1,000 ppm each NO and NO 2 , very low H 2 O levels [3 ppm] in balance air). The mass transfer zone depth exceeded the cumulative 5-inch depth of 4 bed segments, which is deeper than the 2-4 inch depth estimated for the mass transfer zone for adsorbing I 2 using AgZ in prior deep-bed tests. The maximum iodine adsorption capacity for the AgZ under the conditions of this test was 6.2% (6.2 g adsorbed I per 100 g sorbent). The maximum Ag utilization was 51%. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

Electrodeposition as an alternate method for preparation of environmental samples for iodide by AMS

Energy Technology Data Exchange (ETDEWEB)

Adamic, M.L., E-mail: Mary.Adamic@inl.gov [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States); Lister, T.E.; Dufek, E.J.; Jenson, D.D.; Olson, J.E. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States); Vockenhuber, C. [Laboratory of Ion Beam Physics, ETH Zurich, Otto-Stern-Weg 5, 8093 Zurich (Switzerland); Watrous, M.G. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States)

2015-10-15

This paper presents an evaluation of an alternate method for preparing environmental samples for {sup 129}I analysis by accelerator mass spectrometry (AMS) at Idaho National Laboratory. The optimal sample preparation method is characterized by ease of preparation, capability of processing very small quantities of iodide, and ease of loading into a cathode. Electrodeposition of iodide on a silver wire was evaluated using these criteria. This study indicates that the electrochemically-formed silver iodide deposits produce ion currents similar to those from precipitated silver iodide for the same sample mass. Precipitated silver iodide samples are usually mixed with niobium or silver powder prior to loading in a cathode. Using electrodeposition, the silver is already mixed with the sample and can simply be picked up with tweezers, placed in the sample die, and pressed into a cathode. The major advantage of this method is that the silver wire/electrodeposited silver iodide is much easier to load into a cathode.

Electrodeposition as an alternate method for preparation of environmental samples for iodide by AMS

International Nuclear Information System (INIS)

Adamic, M.L.; Lister, T.E.; Dufek, E.J.; Jenson, D.D.; Olson, J.E.; Vockenhuber, C.; Watrous, M.G.

2015-01-01

This paper presents an evaluation of an alternate method for preparing environmental samples for "1"2"9I analysis by accelerator mass spectrometry (AMS) at Idaho National Laboratory. The optimal sample preparation method is characterized by ease of preparation, capability of processing very small quantities of iodide, and ease of loading into a cathode. Electrodeposition of iodide on a silver wire was evaluated using these criteria. This study indicates that the electrochemically-formed silver iodide deposits produce ion currents similar to those from precipitated silver iodide for the same sample mass. Precipitated silver iodide samples are usually mixed with niobium or silver powder prior to loading in a cathode. Using electrodeposition, the silver is already mixed with the sample and can simply be picked up with tweezers, placed in the sample die, and pressed into a cathode. The major advantage of this method is that the silver wire/electrodeposited silver iodide is much easier to load into a cathode.

Effect of 241-americium on bone marrow stroma

International Nuclear Information System (INIS)

Heuvel, R. van den

1990-01-01

The regulation of haemopoiesis occurs via complex interactions between the stroma and the haemopoietic cells. An attempt to further clarifying the mechanisms and the exact role of the stroma in the regulation was made in a study. Results revealed that the murine bone marrow stromal cells are highly radiosensitive after injection with 241-americium and can thus be considered as a target population after internal contamination. In addition, observations are made which may be important for risk estimation for the developing animal and during pregnancy. Contamination in utero and by lactation shows persistent damage up to 1 year after contamination at an average annual dose of 5 cGy. (author)

The extraction of lanthanides and americium by benzyldiakylamines and benzyltrialkylammonium nitrates from the nitrate solutions; structure and aggregation of their salts

International Nuclear Information System (INIS)

Jedinakova, V.; Zilkova, J.; Dvorak, Z.; Vojtiskova, M.

1982-01-01

Benzyldialkylamine and benzyltrialkylammonium nitrates were used for the extraction of lanthanides and americium from aqueous nitrate solutions. The dependence of the extraction performance for Ln(III) and Am(III) on the concentration of nitric acid, the kind and concentration of salting-out agents in the aqueous phase, and the kind of solvent were investigated. The extraction of Am(III) is compared with the extraction of lanthanides. The difference in distribution coefficients for lanthanides and americium can be utilized for the separation of lanthanides and americium. Using vapor phase osmometry and cryoscopy the association of these compounds was measured at 5.5deg, 25deg and 37deg C, allowing rough estimates of ΔH and ΔS for the formation of the aggregates, monomers in the case of benzyldiethylamine, benzyldibutylamine, benzyldihexylamine and benzyldioctylamine, tetramers for the benzyldibutylamine nitrate and tetramers for benzyldimethyldodecylammonium nitrate. (author)

Pretreatment of americium/curium solutions for vitrification

International Nuclear Information System (INIS)

Rudisill, T.S.

1996-01-01

Vitrification will be used to stabilize an americium/curium (Am/Cm) solution presently stored in F-Canyon for eventual transport to the heavy isotope programs at Oak Ridge National Laboratory. Prior to vitrification, an in-tank oxalate precipitation and a series of oxalic/nitric acid washes will be used to separate these elements and lanthanide fission products from the bulk of the uranium and metal impurities present in the solution. Pretreatment development experiments were performed to understand the behavior of the lanthanides and the metal impurities during the oxalate precipitation and properties of the precipitate slurry. The results of these experiments will be used to refine the target glass composition allowing optimization of the primary processing parameters and design of the solution transfer equipment

Autoradiolytic decomposition and reductant-free sodium sup 124 I- and sup 123 I-iodide

Energy Technology Data Exchange (ETDEWEB)

Sajjad, M.; Lambrecht, R.M.; Bakr, S.A. (King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Radionuclide and Cyclotron Operations)

1990-01-01

The presence of salts and metal cations in {sup 124}I- and {sup 123}I-sodium iodide solutions separated from {sup 124}Te targets promots autoradiolytic decomposition of iodide to several different iodine species dependent upon the chemical environment. The stabilization of the radioiodine as iodide by removal of trace salts and trace metal cations and in the absence of reducing agents is described. The high specific activity {sup 123}I- and {sup 124}I-iodide is suitable for labeling antibodies, proteins and radiopharmaceuticals. (orig.).

An investigation of sodium iodide solubility in sodium-stainless steel systems

International Nuclear Information System (INIS)

Sagawa, Norihiko; Tashiro, Suguru

1996-01-01

Sodium iodide and major constituents of stainless steel in sodium are determined by using the steel capsules to obtain a better understanding on contribution of the constituents to the apparent iodide solubility in sodium. The capsule loaded with 20 g sodium and 0.1 - 0.3 g powder of sodium iodide is heated at its upper part in a furnace and cooled at its bottom on brass plates to establish a large temperature gradient along the capsule tube. After a given period of equilibration, the iodide and constituents are fixed in solidified sodium by quick quenching of the capsules. Sodium samples are taken from the sectioned capsule tube and submitted to sodium dissolution by vaporized water for determination of the iodine and to vacuum distillation for determination of the metal elements. Iron and nickel concentrations are observed to be lower in the samples at higher iodine concentrations. Chromium and manganese concentrations are seen to be insensitive to the iodine concentrations. The observations can be interpreted by a model that sodium oxide combines with metal iodide in sodium to form a complex compound and with consideration that the compound will fall and deposit onto the bottom of the capsule by thermal diffusion. (author)

Consideration of the effect of lymph-node deposition upon the measurement of plutonium and americium in the lungs

International Nuclear Information System (INIS)

Falk, R.B.; Lagerquist, C.R.

1975-01-01

Measurement of an inhaled radionuclide by external photon counting includes quantities which may be contained in lymph nodes, as well as quantities in the lungs. An overestimate of the lung burden can result, if a portion of the radionuclide were present in the lymph nodes. This problem is analyzed with respect to the measurement of inhaled plutonium containing plutonium-241 and americium-241, when americium-241 has been used as a tracer for the plutonium. Equations are derived which yield the amounts of americium and of plutonium in the lungs and in the lymph nodes as a function of time after exposure and for various translocation and retention parameters. Count histories (count profiles) of actual exposure cases are compared with calculated count profiles in order to gain insight into possible values of the translocation and retention parameters. Comparison is also made with calculated count profiles using values of translocation and retention parameters recommended by the International Commission on Radiological Protection (ICRP) for use with the Task Group Lung Model. The magnitude of the possible overestimate (error factor) was calculated for combinations o []parameters which yielded matches to the observed count histories. (auth)

On the influence of the americium isotopic vector on the cooling time of minor actinides bearing blankets in fast reactors

Directory of Open Access Journals (Sweden)

Kooyman Timothée

2018-01-01

Full Text Available In the heterogeneous minor actinides transmutation approach, the nuclei to be transmuted are loaded in dedicated targets often located at the core periphery, so that long-lived heavy nuclides are turned into shorter-lived fission products by fission. To compensate for low flux level at the core periphery, the minor actinides content in the targets is set relatively high (around 20 at.%, which has a negative impact on the reprocessing of the targets due to their important decay heat level. After a complete analysis of the main contributors to the heat load of the irradiated targets, it is shown here that the choice of the reprocessing order of the various feeds of americium from the fuel cycle depends on the actual limit for fuel reprocessing. If reprocessing of hot targets is possible, it is more interesting to reprocess first the americium feed with a high 243Am content in order to limit the total cooling time of the targets, while if reprocessing of targets is limited by their decay heat, it is more interesting to wait for an increase in the 241Am content before loading the americium in the core. An optimization of the reprocessing order appears to lead to a decrease of the total cooling time by 15 years compared to a situation where all the americium feeds are mixed together when two feeds from SFR are considered with a high reprocessing limit.

Evaluation of quaternary ammonium halides for removal of methyl iodide from flowing air streams

International Nuclear Information System (INIS)

Freeman, W.P.; Mohacsi, T.G.; Kovach, J.L.

1985-01-01

The quaternary ammonium halides of several tertiary amines were used as impregnants on activated carbon and were tested for methyl iodide penetration in accordance with test Method A, ASTM D3803, 1979, ''Standard Test Methods for Radio-iodine Testing of Nuclear Grade Gas Phase Adsorbents''. The results suggest that the primary removal mechanism for methyl iodide-131 is isotopic exchange with the quaternary ammonium halide. For example, a 5 wt% impregnation of each of the tetramethyl, tetraethyl, tetrapropyl and tetrabutyl ammonium iodides on activated carbon yielded percent penetrations of 0.47, 0.53, 0.78, and 0.08 respectively when tested according to Method A of ASTM D3803. A sample impregnated with 5% tetramethyl ammonium hydroxide gave a methyl iodide penetration of 64.87%, thus supporting the isotopic exchange mechanism for removal. It has been a generally held belief that the success of tertiary amines as impregnants for radioiodine removal is a result of their ability to complex with the methyl iodide. The results of the work indicates that the superiority of the tertiary amines similar to triethylene diamine and quinuclidine, when compared to their straight chain analogs, is a result of their ease in reacting with methyl iodide-127 to form the quaternary ammonium iodide followed by isotopic exchange

Sorption of plutonium and americium on repository, backfill and geological materials relevant to the JNFL low-level radioactive waste repository at Rokkasho-Mura

International Nuclear Information System (INIS)

Baston, G.M.N.; Berry, J.A.; Brownsword, M.; Heath, T.G.; Tweed, C.J.; Williams, S.J.

1995-01-01

An integrated program of batch sorption experiments and mathematical modeling has been carried out to study the sorption of plutonium and americium on a series of repository, backfill and geological materials relevant to the JNFL low-level radioactive waste repository at Rokkasho-Mura. The sorption of plutonium and americium on samples of concrete, mortar, sand/bentonite, tuff, sandstone and cover soil has been investigated. In addition, specimens of bitumen, cation and anion exchange resins, and polyester were chemically degraded. The resulting degradation product solutions, alongside solutions of humic and isosaccharinic acids were used to study the effects on plutonium sorption onto concrete, sand/bentonite and sandstone. The sorption behavior of plutonium and americium has been modeled using the geochemical speciation program HARPHRQ in conjunction with the HATCHES database

National low-level waste management program radionuclide report series, Volume 14: Americium-241

International Nuclear Information System (INIS)

Winberg, M.R.; Garcia, R.S.

1995-09-01

This report, Volume 14 of the National Low-Level Waste Management Program Radionuclide Report Series, discusses the radiological and chemical characteristics of americium-241 ( 241 Am). This report also includes discussions about waste types and forms in which 241 Am can be found and 241 Am behavior in the environment and in the human body

FY-2015 Methyl Iodide Deep-Bed Adsorption Test Report

Energy Technology Data Exchange (ETDEWEB)

Soelberg, Nicholas Ray [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-09-30

Nuclear fission produces fission and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2015 according to a multi-laboratory methyl iodide adsorption test plan. Updates to the deep-bed test system have also been performed to enable the inclusion of evaporated HNO₃ and increased NO₂ concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced silver zeolite (AgZ) resulted in initial iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) under 1,000 for the conditions of the long-duration test performed this year (45 ppm CH3I, 1,000 ppm each NO and NO₂, very low H₂O levels [3 ppm] in balance air). The mass transfer zone depth exceeded the cumulative 5-inch depth of 4 bed segments, which is deeper than the 2-4 inch depth estimated for the mass transfer zone for adsorbing I₂ using AgZ in prior deep-bed tests. The maximum iodine adsorption capacity for the AgZ under the conditions of this test was 6.2% (6.2 g adsorbed I per 100 g sorbent). The maximum Ag utilization was 51%. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

Discovery of aryl-tri-fluoroborates as potent sodium/iodide sym-porter (NIS) inhibitors

International Nuclear Information System (INIS)

Lecat-Guillet, N.; Ambroise, Y.

2008-01-01

The structure-based design of sodium/iodide sym-porter (NIS) inhibitors identified new active compounds. The organo-tri-fluoroborate shown was found to inhibit iodide uptake with an IC50 value of 0.4 μM on rat-derived thyroid cells. The biological activity is rationalized by the presence of the BF3 - ion as a minimal binding motif for substrate recognition at the iodide binding site. (authors)

Discovery of aryl-tri-fluoroborates as potent sodium/iodide sym-porter (NIS) inhibitors

Energy Technology Data Exchange (ETDEWEB)

Lecat-Guillet, N.; Ambroise, Y. [CEA, DSV, Dept Bioorgan Chem and Isotop Labelling, Inst Biol and Technol, iBiTecS, F-91191 Gif Sur Yvette (France)

2008-07-01

The structure-based design of sodium/iodide sym-porter (NIS) inhibitors identified new active compounds. The organo-tri-fluoroborate shown was found to inhibit iodide uptake with an IC50 value of 0.4 {mu}M on rat-derived thyroid cells. The biological activity is rationalized by the presence of the BF3{sup -} ion as a minimal binding motif for substrate recognition at the iodide binding site. (authors)

Determination of americium and plutonium in autopsy tissue: methods and problems

International Nuclear Information System (INIS)

Boyd, H.A.; Eutsler, B.C.; McInroy, J.F.

1979-01-01

The current methods used by the tissue analysis program at LASL for the determination of americium and plutonium in autopsy tissue are described. Problems affecting radiochemical yield are discussed. Included are problems associated with sample preparation, separation of plutonium from large amounts of bone ash, and reagent contamination. The average 242 Pu tracer yield for 1800 Pu determinations is 78 +- 12%. The average 242 Am tracer yield is 85 +- 7% for 40 determinations

Determination by gamma-ray spectrometry of the plutonium and americium content of the Pu/Am separation scraps. Application to molten salts; Determination par spectrometrie gamma de la teneur en plutonium et en americium de produits issus de separation Pu/Am. Application aux bains de sels

Energy Technology Data Exchange (ETDEWEB)

Godot, A. [CEA Valduc, Dept. de Traitement des Materiaux Nucleaires, 21 - Is-sur-Tille (France); Perot, B. [CEA Cadarache, Dept. de Technologie Nucleaire, Service de Modelisation des Transferts et Mesures Nucleaires, 13 - Saint-Paul-lez-Durance (France)

2005-07-01

Within the framework of plutonium recycling operations in CEA Valduc (France), americium is extracted from molten plutonium metal into a molten salt during an electrolysis process. The scraps (spent salt, cathode, and crucible) contain extracted americium and a part of plutonium. Nuclear material management requires a very accurate determination of the plutonium content. Gamma-ray spectroscopy is performed on Molten Salt Extraction (MSE) scraps located inside the glove box, in order to assess the plutonium and americium contents. The measurement accuracy is influenced by the device geometry, nuclear instrumentation, screens located between the sample and the detector, counting statistics and matrix attenuation, self-absorption within the spent salt being very important. The purpose of this study is to validate the 'infinite energy extrapolation' method employed to correct for self-attenuation, and to detect any potential bias. We present a numerical study performed with the MCNP computer code to identify the most influential parameters and some suggestions to improve the measurement accuracy. A final uncertainty of approximately 40% is achieved on the plutonium mass. (authors)

A new method for the determination of plutonium and americium using high pressure microwave digestion and alpha-spectrometry or ICP-SMS

International Nuclear Information System (INIS)

Luisier, F.; Corcho Alvarado, J.A.; Froidevaux, P.; Steinmann, P.; Krachler, M.

2009-01-01

Plutonium and americium are radionuclides particularly difficult to measure in environmental samples because they are a-emitters and therefore necessitate a careful separation before any measurement, either using radiometric methods or ICP-SMS. Recent developments in extraction chromatography resins such as Eichrom R TRU and TEVA have resolved many of the analytical problems but drawbacks such as low recovery and spectral interferences still occasionally occur. Here, we report on the use of the new Eichrom R DGA resin in association with TEVA resin and high pressure microwave acid leaching for the sequential determination of plutonium and americium in environmental samples. The method results in average recoveries of 83 ± 15% for plutonium and 73 ± 22% for americium (n = 60), and a less than 10% deviation from reference values of four IAEA reference materials and three samples from intercomparisons exercises. The method is also suitable for measuring 239 Pu in water samples at the μBq/l level, if ICP-SMS is used for the measurement. (author)

Early effects of external gamma irradiation on iodide metabolism in rat thyroid

International Nuclear Information System (INIS)

Niatsetskaya, Z.; Nadolnik, L.

2006-01-01

Full text of publication follows: The exposure of the thyroid gland to therapeutic doses of external gamma irradiation is frequently associated with thyroid dysfunction. Although late irradiation effects are well documented, little is still known about the early functional alterations in the thyroid subjected to radiation therapy. The aim of this study was to examine the early effect of single external gamma irradiation on iodide metabolism in the thyroid. The Wistar female rats were irradiated using a 60 Co installation with a constant capacity of 0.64 Gy/min. The doses used were 0.25, 0.5, 1, 2, 5 Gy. The animals were sacrificed after 24 hours following the irradiation. T he thyroid organ culture was cultivated during 24 h and than was irradiated with a single dose of 5 Gy. The thyroid tissue was assayed for thyro-peroxidase activity and concentrations of total, free and protein -binding iodide. It was shown that the 0.25 Gy irradiation depressed thyroid iodide uptake, which was manifested in decreasing total iodide by 25%. The same tendency was observed after the 0.5 Gy irradiation. In the 1, 2, 5 Gy groups, the concentrations of total and free iodide increased by 26 -34% and 50-68%, accordingly. The level of protein-binding iodide in these groups was within the control values. However, protein-binding/total iodide and protein binding/ free iodide ratios decreased by 17 -41%, suggesting inhibition of thyroglobulin iodination. Thyro-peroxidase (T.P.O.) plays a key role in thyroid hormone synthesis by catalyzing both the iodination of thyroglobulin and the coupling some of the iodo-tyrosyl residues. After 24 hours on irradiation, a 31.5-54% dose-dependent inhibition of T.P.O. activity was shown in the 1, 2 and 5 Gy groups. The irradiation of the rat thyroid organ culture with a single dose of 5 Gy also led to significant inhibition of T.P.O. by 56.91% after 2 hours. We compared the enzyme kinetics of thyro-peroxidase from thyroid microsomal fraction control and

Linearity and Reversibility of Iodide Adsorption on Sediments from Hanford, Washington Under Water Saturated Conditions

International Nuclear Information System (INIS)

Um, Wooyong; Serne, R. Jeffrey; Krupka, Kenneth M.

2004-01-01

A series of adsorption and desorption experiments were completed to determine the linearity of iodide adsorption, as a function of concentration, and its reversibility onto sediment for geochemical conditions germane to the proposed disposal of low-level radioactive waste by the U.S. Department of Energy's Immobilized Low Activity Waste (ILAW) program at the Hanford Site in southeastern Washington. Iodine-129 is predicted to be one of the top three long-term risk drivers based on past performance assessment conducted for the eventual disposal of the low-level portion of radioactive wastes currently stored in underground storage tanks at Hanford, because iodide exhibits little adsorption affinity to mineral surfaces resulting in high mobility in the subsurface environment. Adsorption experiments, conducted with Hanford formation sediments and groundwater spiked with dissolved 125I (as an analog tracer for 129I), indicated that iodide adsorption was very low at pH 7.5 and could be represented by a linear isotherm up to a total concentration of 100 mg/L dissolved iodide. The linearity of iodide adsorption up to concentrations of 100 mg/L validates the use of the linear Kd construct in transport models to predict the fate and transport of 129I in subsurface systems at Hanford. The results of desorption experiments indicated that up to 60% of adsorbed iodide was readily desorbed after 14 days by the same groundwater solution. Iodide adsorption was considered to be partially reversible or weakly binding on the sediments. Even though small amount of initial iodide is retarded by adsorption reactions at mineral-water interfaces, the weak adsorption affinity results in release of iodide when iodide free pore waters and ground waters contact the contaminated sediments in the vadose zone and aquifer systems

Implications of plutonium and americium recycling on MOX fuel fabrication

International Nuclear Information System (INIS)

Renard, A.; Pilate, S.; Maldague, Th.; La Fuente, A.; Evrard, G.

1995-01-01

The impact of the multiple recycling of plutonium in power reactors on the radiation dose rates is analyzed for the most critical stage in a MOX fuel fabrication plant. The limitation of the number of Pu recycling in light water reactors would rather stem from reactor core physics features. The case of recovering americium with plutonium is also considered and the necessary additions of shielding are evaluated. A comparison between the recycling of Pu in fast reactors and in light water reactors is presented. (author)

Sodium iodide symporter: Its role in nuclear oncology

International Nuclear Information System (INIS)

Chung, June-Key

2004-01-01

Full text: Thyroid iodide uptake is basic to the clinical applications of radioiodine in diagnosis and therapy. Iodide uptake occurs across the membrane of thyroid follicular cells via an active transporter process mediated by the sodium/iodide symporter (NIS). The recent cloning of the gene encoding NIS enabled better characterization of the molecular mechanisms underlying the iodide transport, thus opening the way to clarify and expand its role in medicine. NIS contains 13 transmembrane segments, and its gene encodes a glycoprotein of 643 amino acids. Decreased NIS expression levels account for the reduced iodide uptake in thyroid carcinomas. We found that thyroid cancer patients with positive immunostaining for NIS responded to I-131 therapy better than did the patients with negative immunostaining. Thus, NIS gene can be used for radionuclide gene therapy. Targeted expression of functional NIS in cancer cells would enable these cells to concentrate iodide from plasma and would, therefore, offer the possibility of radioiodine therapy. We and others have shown that gene transfer of NIS into a variety of cell types confers increased radioiodine uptake up to several hundred-fold that of controls. There is great interest in exploring the possibility of NIS gene transfer to facilitate radioiodine therapy for non-thyroidal human cancers including hepatoma, prostate, breast, colon cancers as well as thyroid cancer. Recently, several approaches such as, targeted gene transfer, thyroid peroxidase gene co-transfection, retinoic acid treatment and Re-188 therapy instead of I-131, have been tried to improve this novel gene therapy. Imaging reporter gene is useful in non-invasively determining the location, duration and magnitude of transgene expression in living animal. Conventionally, HSV-tk and dopaminergic receptor (D2R) genes have been presented as possible imaging reporter genes. We proved that NIS could serve as an alternative imaging reporter gene. NIS has many

Iodine K-edge EXAFS analysis of iodide ion-cyclodextrin inclusion complexes in aqueous solution

International Nuclear Information System (INIS)

Kaneko, T; Ueda, M; Nagamatsu, S; Konishi, T; Fujikawa, T; Mizumaki, M

2009-01-01

We study the structure of inclusion complexes of α-, β-, γ-cyclodextrin with mono-iodide ion in aqueous solution by means of iodine K-edge EXAFS spectroscopy. The analysis is based on the assumption that two kinds of iodide ions exist in KI-cyclodextrin aqueous solution i.e. hydrated mono-iodide ions and one-one mono-iodide-cyclodextrin inclusion complexes. In KI-α-cyclodextrin system, iodine K-edge EXAFS analyse show that the average coordination number of the oxygen atoms in water molecules in the first hydration shell decreases as the fraction of included ions increases. This result suggests that dehydration process accompanies the formation of the inclusion complex. This is not found in the case of β-cyclodextrin, indicating that in this case the iodide ions are included together with the whole first hydration shell.

Chemical behaviour of trivalent and pentavalent americium in saline NaCl-solutions. Studies of transferability of laboratory data to natural conditions. Interim report. Reported period: 1.2.1993-31.12.1993; Chemisches Verhalten von drei- und fuenfwertigem Americium in Salinen NaCl-Loesungen. Untersuchung der Uebertragbarkeit von Labordaten auf natuerliche Verhaeltnisse. Zwischenbericht. Berichtszeitraum 1.2.1993-31.12.1993

Energy Technology Data Exchange (ETDEWEB)

Runde, W; Kim, J I

1994-09-15

In order to clarify the chemical behaviour of Americium in saline aqueous systems relevant for final storage this study deals with the chemical reactions of trivalent and pentavalent Americium in NaCl-solutions under the influence of radiolysis from its own alpha radiation. The focus of the study was on investigating the geologically relevant reactions, such as hydrolysis or carbonate- and chloride complexing in solid-liquid equilibriums. Comprehensive measurements on solubility and spectroscopic studies in NaCl-solutions were carried out in a CO{sub 2}-free atmosphere and 10{sup -2} atm CO{sub 2} partial pressure. Identification and characterisation of the AM (III) and AM(V) solid phases were supplemented by structural research with the chemically analogue EU (III) and Np(V) compounds. The alpha-radiation induced radiolysis in saline NaCl solutions and the redox behaviour of Americium which was influenced thereby were spectroscopically quantified. (orig.) [Deutsch] Zur Klaerung des chemischen Verhaltens von Americium in endlagerrelevanten salinen aquatischen Systemen befasst sich die vorliegende Arbeit mit den chemischen Reaktionen des drei- und fuenfwertigen Americiums in NaCl-Loesungen unter dem Einfluss der Radiolyse durch die eigene {alpha}-Strahlung. Der Schwerpunkt dieser Arbeit lag auf der Untersuchung der geologisch relevanten Reaktionen, wie Hydrolyse sowie Carbonat- und Chloridkomplexierung in fest-fluessig Gleichgewichtssystemen. Hierzu wurden umfassende Loeslichkeitsmessungen und spektroskopische Untersuchungen in NaCl-Loesungen, sowohl unter CO{sub 2}-freier Atmosphaere als auch unter 10{sup -2} atm CO{sub 2}-Partialdruck, durchgefuehrt. Die Identifizierung und Charakterisierung der Am(III)- und Am(V)-Festphasen wurde ergaenzt durch strukturelle Untersuchungen mit den chemisch analogen Eu(III)- und Np(V)-Verbindungen. Die von der {alpha}-Strahlung induzierte Radiolyse in salinen NaCl-Loesungen und das dadurch beeinflusste Redoxverhalten von Americium

Americium/Curium Vitrification Pilot Tests - Part II

International Nuclear Information System (INIS)

Marra, J.E.; Baich, M.A.; Fellinger, A.P.; Hardy, B.J.; Herman, D.T.; Jones, T.M.; Miller, C.B.; Miller, D.H.; Snyder, T. K.; Stone, M.E.

1998-05-01

Isotopes of americium (Am) and curium (Cm) were produced in the past at the Savannah River Site (SRS) for research, medical, and radiological applications. These highly radioactive and valuable isotopes have been stored in an SRS reprocessing facility for a number of years. Vitrification of this solution will allow the material to be more safely stored until it is transported to the DOE Oak Ridge Reservation for use in research and medical applications. A previous paper described operation results from the Am-Cm Melter 2A pilot system, a full-scale non-radioactive pilot facility. This paper presents the results from continued testing in the Pilot Facility and also describes efforts taken to look at alternative vitrification process operations and flowsheets designed to address the problems observed during melter 2A pilot testing

Behavior of americium in aqueous carbonate systems

Energy Technology Data Exchange (ETDEWEB)

Silva, R.J.

1983-11-01

The solubilities of crystalline Am(OH)/sub 3/ and AmOHCO/sub 3/ were measured at 25/sup 0/C in aqueous solutions of 0.1 M NaClO/sub 4/ by determination of the solution concentrations of Am. Prior to use in the measurements, the solid materials were characterized by their x-ray powder diffraction patterns. The solubility product quotients were calculated from the experimental data. The hydrolysis quotients of Am/sup 3 +/ were also estimated from the hydroxide solubility data. Using the thermodynamic data derived from these experiments and the recently reported formation constants for the Am/sup 3 +/ carbonate complexes, the solid phases and concentrations of solution species of americium in several aqueous carbonate systems were calculated using the computer code MINEQL. 20 references, 1 figure, 1 table.

Worldwide bioassay data resources for plutonium/americium internal dosimetry studies

International Nuclear Information System (INIS)

Miller, G.; Bertelli, L.; Little, T.; Guilmette, R.; Riddell, T.; Filipy, R.

2005-01-01

Full text: Biokinetic models are the scientific underpinning of internal dosimetry. These models describe how materials of interest taken into the body by various routes (for example inhalation) are transported through the body, allowing the modelling of bioassay measurements and the estimation of radiation dose. The International Commission on Radiation Protection (ICRP) publishes biokinetic models for use in internal dosimetry. These models represent the consensus judgement of a committee of experts, based on human and animal data. Nonetheless, it is important to validate biokinetic models using directly applicable data, in a scientifically transparent manner, especially for internal dosimetry research purposes (as opposed to radiation protection), as in epidemiology studies. Two major goals would be to determine individual variations of model parameters for the purpose of assessing this source of uncertainty in internal dose calculations, and to determine values of workplace specific parameters (such as particle solubility in lung fluids) for different representative workplaces. Furthermore, data on the observed frequency of intakes under various conditions can be used in the interpretation of bioassay data. All of the above may be couched in the terminology of Bayesian statistical analysis and amount to the determination of the Bayesian prior probability distributions needed in a Bayesian interpretation of bioassay data. The authors have direct knowledge of several significant databases of plutonium/americium bioassay data (including autopsy data). The purpose of this paper is to acquaint the worldwide community with these resources and to invite others who may know of other such databases to participate with us in a publication that would document the content, form, and the procedures for seeking access to these databases. These databases represent a tremendous scientific resource in this field. Examples of databases known to the authors include: the

XRD monitoring of α self-irradiation in uranium-americium mixed oxides.

Science.gov (United States)

Horlait, Denis; Lebreton, Florent; Roussel, Pascal; Delahaye, Thibaud

2013-12-16

The structural evolution under (241)Am self-irradiation of U(1-x)Am(x)O(2±δ) transmutation fuels (with x ≤ 0.5) was studied by X-ray diffraction (XRD). Samples first underwent a preliminary heat treatment performed under a reducing atmosphere (Ar/H2(4%)) aiming to recover the previously accumulated structural defects. Over all measurements (carried out over up to a full year and for integrated doses up to 1.5 × 10(18) α-decay events·g(-1)), only fluorite U(1-x)Am(x)O(2±δ) solid solutions were observed. Within a few days after the end of the heat treatment, each of the five studied samples was slowly oxidized as a consequence of their move to air atmosphere, which is evidenced by XRD by an initial sharp decrease of the unit cell parameter. For the compounds with x ≤ 0.15, this oxidation occurred without any phase transitions, but for U0.6Am0.4O(2±δ) and U0.5Am0.5O(2±δ), this process is accompanied by a transition from a first fluorite solid solution to a second oxidized one, as the latter is thermodynamically stable in ambient conditions. In the meantime and after the oxidation process, (241)Am α self-irradiation caused a structural swelling up to ∼0.8 vol %, independently of the sample composition. The kinetic constants of swelling were also determined by regression of experimental data and are, as expected, dependent on x and thus on the dose rate. The normalization of these kinetic constants by sample α-activity, however, leads to very close swelling rates among the samples. Finally, evolutions of microstrain and crystallite size were also monitored, but for the considered dose rates and cumulated doses, α self-irradiation was found, within the limits of the diffractometer used, to have almost no impact on these characteristics. Microstrain was found to be influenced instead by the americium content in the materials (i.e., by the impurities associated with americium starting material and the increase of cationic charge heterogeneity with

Clinical value of sodium iodide symporter

International Nuclear Information System (INIS)

Li Qian

2003-01-01

The sodium iodide symptorter (NIS) is a membrane glycoprotein that mediates iodide uptake in the thyroid gland and several extrathyroidal tissues. In addition to thyroid tissues, the expression of NIS is found in stomach, prostate, placenta and so on. Radioiodine-concentrating activity in thyroid tissues has allowed the use of radioiodine as a diagnostic and therapeutic agent for patients with thyroid disorders. However, some extrathyroid tissues also take up radioiodine, contributing to unwanted side effects of radioiodine therapy. Now that the molecule of NIS has been cloned and characterized, it may be possible to develop novel strategies to differentially modulate NIS expression and activity, enhancing it in target tissues and impeding it in others. It is also important to explore the use of NIS as an imaging reporter gene to monitor the expression profile of the transgene in transgenic mouse animal models and in patients undergoing gene therapy clinical trials

Iodide-induced thyrotoxicosis in a thyroidectomized patient with metastatic thyroid carcinoma

Energy Technology Data Exchange (ETDEWEB)

Yoshinari, M.; Tokuyama, T.; Okamura, K.; Sato, K.; Kusuda, K.; Fujishima, M.

1988-04-15

An unusual case of iodide-induced thyrotoxicosis is documented in this article. The patient was a 64-year-old euthyroid man with acromegaly. He also had multiple follicular and papillary thyroid carcinomas with a metastatic lesion in the lumbar vertebrae. After a total thyroidectomy, he became slightly hypothyroid, and the lumbar lesion began to incorporate /sup 131/I by scintigraphy. When an iodine-containing contrast medium happened to be injected, a transient increase of serum thyroid hormone level was observed. After complete thyroid ablation with 83 mCi of /sup 131/I, the oral administration of 100 mg of potassium iodide for 7 days induced a prominent increase of serum thyroid hormone level. These findings indicated that the metastatic thyroid carcinoma could produce excess thyroid hormone insofar as a sufficient amount of iodide was given. Although this is the first report of such a case, iodide-induced thyrotoxicosis may not be rare in patients with thyroid carcinomas because the Wolff-Chaikoff effect is thought to be lost, and the organic iodinating activity and lysosomal protease activity are well-preserved.

Iodide-induced thyrotoxicosis in a thyroidectomized patient with metastatic thyroid carcinoma

International Nuclear Information System (INIS)

Yoshinari, M.; Tokuyama, T.; Okamura, K.; Sato, K.; Kusuda, K.; Fujishima, M.

1988-01-01

An unusual case of iodide-induced thyrotoxicosis is documented in this article. The patient was a 64-year-old euthyroid man with acromegaly. He also had multiple follicular and papillary thyroid carcinomas with a metastatic lesion in the lumbar vertebrae. After a total thyroidectomy, he became slightly hypothyroid, and the lumbar lesion began to incorporate 131 I by scintigraphy. When an iodine-containing contrast medium happened to be injected, a transient increase of serum thyroid hormone level was observed. After complete thyroid ablation with 83 mCi of 131 I, the oral administration of 100 mg of potassium iodide for 7 days induced a prominent increase of serum thyroid hormone level. These findings indicated that the metastatic thyroid carcinoma could produce excess thyroid hormone insofar as a sufficient amount of iodide was given. Although this is the first report of such a case, iodide-induced thyrotoxicosis may not be rare in patients with thyroid carcinomas because the Wolff-Chaikoff effect is thought to be lost, and the organic iodinating activity and lysosomal protease activity are well-preserved

The value of iodide as a parameter in the chemical characterisation of groundwaters

Science.gov (United States)

Lloyd, J. W.; Howard, K. W. F.; Pacey, N. R.; Tellam, J. H.

1982-06-01

Brackish and saline groundwaters can severely constrain the use of fresh groundwaters. Their chemical characterisation is important in understanding the hydraulic conditions controlling their presence in an aquifer. Major ions are frequently of limited value but minor ions can be used. Iodide in groundwater is particularly significant in many environments due to the presence of soluble iodine in aquifer matrix materials. Iodide is found in groundwaters in parts of the English Chalk aquifer in concentrations higher than are present in modern seawater. Its presence is considered as a indication of groundwater residence and is of use in the characterisation of fresh as well as saline waters. Under certain circumstances modern seawater intrusion into aquifers along English estuaries produces groundwaters which are easily identified due to iodide enrichment from estuarine muds. In other environments iodide concentrations are of value in distinguishing between groundwaters in limestones and shaly gypsiferous rocks as shown by a study in Qatar, while in an alluvial aquifer study in Peru iodide has been used to identify groundwaters entering the aquifer from adjacent granodiorites.

Lead iodide X-ray and gamma-ray spectrometers for room and high temperature operation

International Nuclear Information System (INIS)

Hermon, H.; James, R.B.; Lund, J.

1998-01-01

In this study the authors report on the results of the investigation of lead iodide material properties. The effectiveness of a zone refining purification method on the material purity is determined by ICP-MS and ICP-OES and correlated to the electrical and physical material properties. They show that this zone refining method is very efficient in removing impurities from lead iodide, and they also determine the segregation coefficient for some of these impurities. Triple axis X-ray diffraction (TAD) analysis has been used to determine the crystalline perfection of the lead iodide after applying various cutting, etching and fabrication methods. The soft lead iodide crystal was found to be damaged when cleaved by a razor blade, but by using a diamond wheel saw, followed by etching, the crystallinity of the material was much improved, as observed by TAD. Low temperature photoluminescence also indicates an improvement in the material properties of the purified lead iodide. Electrical properties of lead iodide such as carrier mobility, were calculated based on carrier-phonon scattering. The results for the electrical properties were in good agreement with the experimental data

Development of analytical methods for the separation of plutonium, americium, curium and neptunium from environmental samples

Energy Technology Data Exchange (ETDEWEB)

Salminen, S.

2009-07-01

In this work, separation methods have been developed for the analysis of anthropogenic transuranium elements plutonium, americium, curium and neptunium from environmental samples contaminated by global nuclear weapons testing and the Chernobyl accident. The analytical methods utilized in this study are based on extraction chromatography. Highly varying atmospheric plutonium isotope concentrations and activity ratios were found at both Kurchatov (Kazakhstan), near the former Semipalatinsk test site, and Sodankylae (Finland). The origin of plutonium is almost impossible to identify at Kurchatov, since hundreds of nuclear tests were performed at the Semipalatinsk test site. In Sodankylae, plutonium in the surface air originated from nuclear weapons testing, conducted mostly by USSR and USA before the sampling year 1963. The variation in americium, curium and neptunium concentrations was great as well in peat samples collected in southern and central Finland in 1986 immediately after the Chernobyl accident. The main source of transuranium contamination in peats was from global nuclear test fallout, although there are wide regional differences in the fraction of Chernobyl-originated activity (of the total activity) for americium, curium and neptunium. The separation methods developed in this study yielded good chemical recovery for the elements investigated and adequately pure fractions for radiometric activity determination. The extraction chromatographic methods were faster compared to older methods based on ion exchange chromatography. In addition, extraction chromatography is a more environmentally friendly separation method than ion exchange, because less acidic waste solutions are produced during the analytical procedures. (orig.)

Structural templating in a nonplanar phthalocyanine using single crystal copper iodide

OpenAIRE

Rochford, L. A. (Luke A.); Ramadan, Alexandra J.; Keeble, Dean S.; Ryan, Mary P.; Heutz, Sandrine; Jones, T. S. (Tim S.)

2015-01-01

Solution-grown copper iodide crystals are used as substrates for the templated growth of the nonplanar vanadyl phthalocyanine using organic molecular beam deposition. Structural characterization reveals a single molecular orientation produced by the (111) Miller plane of the copper iodide crystals. These fundamental measurements show the importance of morphology and structure in templating interactions for organic electronics applications.

Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

Energy Technology Data Exchange (ETDEWEB)

Holm, J.; Ekberg, C. (Chalmers Univ. of Technology, Goeteborg (Sweden)); Kaerkelae, T.; Auvinen, A. (VTT, Espoo (Finland)); Glaenneskog, H. (Vattenfall Power Consultant, Goeteborg (Sweden))

2011-05-15

An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment, was started. During year 2008 (NROI-1) the radiolytic oxidation of elemental iodine was investigated and during 2009 (NROI-2), the radiolytic oxidation of organic iodine was studied. This project (NROI-3) is a continuation of the investigation of the oxidation of organic iodine. The project has been divided into two parts. 1. The aims of the first part were to investigate the effect of ozone and UV-radiation, in dry and humid conditions, on methyl iodide. 2. The second project was about gamma radiation (approx20 kGy/h) and methyl iodide in dry and humid conditions. 1. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UV-radiation intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. The particle formation was instant and extensive when methyl iodide was exposed to ozone and/or radiation at all temperatures. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-200 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine oxides (I{sub xO{sub y}). However, the correct speciation of the formed particles was difficult to obtain because the particles melted and fused together under the electron beam. 2. The results from this sub-project are more inconsistent and hard to interpret. The particle formation was significant lesser than corresponding experiments when ozone/UV-radiation was used instead of gamma radiation. The transport of gaseous methyl iodide through the facility was

Gravimetric determination of cadmium with o-phenanthroline and iodide

International Nuclear Information System (INIS)

Yoshida, Hitoshi; Mizuno, Kazunori; Taga, Mitsuhiko; Hikime, Seiichiro

1976-01-01

Cadmium forms insoluble mixed ligand complex with o-phenanthroline and iodide ions. By using the complex a new gravimetric method for the determination of cadmium was investigated. The recommended analytical procedure is as follows: Adjust pH value of a solution containing 5 to 45 mg cadmium to 4 with 3 M acetic acid-sodium acetate buffer solution. Add over threefold moles of potassium iodide to the solution and heat to just before boiling. To the solution add 0.1% ascorbic acid solution and then 0.1 M o-phenanthroline solution drop by drop in excess with stirring, and cool the mixture to room temperature. Filter the precipitates and wash first with 0.01% potassium iodide solution and then with water. Dry the precipitates at 110 0 C for two hours and weigh as Cd(o-phen) 2 I 2 (I). The gravimetric factor of the complex for cadmium is 0.1547. Chemical composition of the precipitate is variable when o-phenanthroline is added less than twofold moles to cadmium. Adding the o-phenanthroline solution 2.4-fold moles against cadmium, the ternary complex (I) precipitates quantitatively. Though a large excess of iodide ion in the solution contaminated the precipitate, the contamination was avoided when precipitation was carryed out at high temperature and in the presence of ascorbic acid. By the presented procedure 5 to 45 mg of cadmium are determined with a standard deviation of 0 C. (JPN)

Trapping radiodine, in the form of methyl iodide, on nuclear carbon

Energy Technology Data Exchange (ETDEWEB)

Nacapricha, D. [Mahidol Univ., Bangkok (Thailand); Taylor, C. [John Moores Univ., Liverpool (United Kingdom)

1996-12-31

Studies have been performed on potassium-iodide-impregnated charcoals of the type used in the nuclear industry for trapping radioiodine released during nuclear fission. The effects of various parameters on the trapping efficiency of methyl iodide have been investigated. A variation in particle size within a bulk charcoal caused poor precision in K value measurements because of differences in surface area, pore volume, and bed density, leading to differences in the deposition of the impregnant. Precision is improved by sieving the charcoal to a narrower size because smaller particles have a higher porosity. This finding is supported by surface area and pore measurements. Two methods of impregnation are compared by measuring K values and the deposition of potassium iodide. Charcoal impregnated by rotary evaporation exhibits both higher K values and higher potassium iodide contents than sprayed charcoal. Two designs of spraying drum are compared: a drum with helical vanes allows more efficient deposition and more uniform distribution of impregnant than a drum with axial vanes. A decrease in the K value with increasing humidity correlates with the available surface area. A similar correlation exists between water content and available pore volume. Aging of potassium-iodide-impregnated charcoal, caused by the formation of oxygen complexes on the surface, is associated with significant falls in K value. K values of charcoals also can be restored to at least their original values by heat treatment in the absence of air. 12 refs., 6 figs., 1 tab.

Functional activity of human sodium/iodide symporter in tumor cell lines

International Nuclear Information System (INIS)

Petrich, T.; Knapp, W.H.; Poetter, E.

2003-01-01

Aim: The sodium/iodide symporter (NIS) actively transports iodide into thyrocytes. Thus, NIS represents a key protein for diagnosis and radioiodine therapy of differentiated thyroid cancer. Additionally, in the future the NIS gene may be used for cancer gene therapy of non-thyroid-derived malignancies. In this study we evaluated the functionality of NIS with respect to iodide uptake in a panel of tumor cell lines and compared this to gene transfer efficiency. Methods: A human NIS-containing expression vector and reporter-gene vectors encoding and beta;-Galactosidase- or EGFP were used for transient transfection of 13 tumor cell lines. Following transfection measurements of NIS-mediated radioiodide uptake using Na 125 I and of transfection efficiency were performed. The latter included β;-Galactosidase activity measurements using a commercial kit and observation by fluorescence microscopy for EGFP expression. Results: In contrast to respective parental cells, most NIS-transfected cell lines displayed high, perchlorate-sensitive radioiodide uptake. Differences in radioiodide uptake between cell lines apparently corresponded to transfection efficiencies, as judged from reporter-gene assays. Conclusion: With respect to iodide uptake we provide evidence that NIS is functional in different cellular context. As iodide uptake capacity appears to be well correlated to gene transfer efficiency, cell type-specific actions on NIS (e. g. post-translational modification such as glycosylation) are not inhibitory to NIS function. Our data support the promising role of NIS in cancer gene therapy strategies. (orig.)

Experimental studies of caesium iodide aerosol condensation: theoretical interpretation

International Nuclear Information System (INIS)

Beard, A.M.; Benson, C.G.; Horton, K.D.; Buckle, E.R.

1990-07-01

Caesium iodide is predicted to be a significant source of fission product aerosols during the course of a severe accident in a pressurised water reactor (PWR). The nucleation and growth of caesium iodide aerosols have been studied using a plume chamber and the results compared with theoretical values calculated using the approach developed by Buckle for aerosol nucleation. The morphology of the particles was studied using scanning electron microscopy (SEM) and transmission optical microscopy (TOM), whilst the particle size distributions were determined from differential mobility (DMPS) and aerodynamic (APS) measurements. (author)

Quantitative determination of americium and curium in solutions using potassium tungstophosphate

International Nuclear Information System (INIS)

Chistyakov, V.M.; Baranov, A.A.; Erin, E.A.; Timoaeev, G.A.

1990-01-01

Two methods of americium (4) and curium (4) titration-replacement and redox ones - have been considered. According to the replacement method thorium nitrate solution was used as a titrant and the final point of titration was determined spectophotometrically. Using the method developed, on the basis of experimental data, the composition of thorium (4) complex with potassium tungstophosphate was determined. In case of the redox titration sodium nitrite was used, and the final titration point was indicated either spectrophotometrically or potentiometrically

Vitrification of F-area americium/curium: feasibility study and preliminary process recommendation

International Nuclear Information System (INIS)

Ramsey, W.G.; Miller, D.; Minichan, R.; Coleman, L.; Schumacher, R.; Hardy, B.; Jones, R.

1994-01-01

Work was performed to identify a process to vitrify the contents of F- canyon Tank 17.1. Tank 17.1 contains the majority of americium (Am) and curium (Cm) contained in the DOE Complex. Oak Ridge National Laboratory (ORNL) has made a formal request for this material as fuel for production of Cf252 and other transplutonium actinides. The Am and Cm (and associated lanthanide fission products) are currently in nitric acid solution. Transportation of the intensely radioactive Am/Cm in liquid form is not considered possible. As a result, the material will either be solidified and shipped to ORNL or discarded to the Tank Farm. Nuclear Materials Processing Technology (NMPT), therefore, requested Defense Waste Processing Technology (DWPT) to determine if the Tank 17.1 material could be vitrified, and if it was vitrified could the americium and curium be successfully recovered. Research was performed to determine if the Tank 17.1 contents could indeed be mixed with glass formers and vitrified. Additional studies identified critical process parameters such as heat loading, melter requirements, off-gas evolution, etc. Discussions with NMPT personnel were initiated to determine existing facilities where this work could be accomplished safely. A process has been identified which will convert the Am/Cm material into approximately 300kg of glass

The transmutation of americium: the Ecrix experiments in Phenix

International Nuclear Information System (INIS)

Garnier, J.C.; Schmidt, N.; Croixmarie, Y.; Ottaviani, J.P.; Varaine, F.; Saint Jean, C. de

1999-01-01

The first americium transmutation experiment in a specific target in PHENIX will occur with the ECRIX-B and ECRIX-H experiments. Beside material testing, the objective is also to represent a concept of transmutation whose specificity is to enhance the kinetics of transmutation by using a moderated spectrum. The moderator materials will be 11 B 4 C and CaH 2 for ECRIX-B and ECRIXH respectively, the irradiation conditions have been predicted for both the neutronics and thermal. The targets (MgO-AmO X pellets) are manufactured in the ATALANTE laboratory and the design is performed according to the PHENIX operating conditions. (authors)

Robotic sample preparation for radiochemical plutonium and americium analyses

International Nuclear Information System (INIS)

Stalnaker, N.; Beugelsdijk, T.; Thurston, A.; Quintana, J.

1985-01-01

A Zymate robotic system has been assembled and programmed to prepare samples for plutonium and americium analyses by radioactivity counting. The system performs two procedures: a simple dilution procedure and a TTA (xylene) extraction of plutonium. To perform the procedures, the robotic system executes 11 unit operations such as weighing, pipetting, mixing, etc. Approximately 150 programs, which require 64 kilobytes of memory, control the system. The system is now being tested with high-purity plutonium metal and plutonium oxide samples. Our studies indicate that the system can give results that agree within 5% at the 95% confidence level with determinations performed manually. 1 ref., 1 fig., 1 tab

In situ characterization of uranium and americium oxide solid solution formation for CRMP process: first combination of in situ XRD and XANES measurements.

Science.gov (United States)

Caisso, Marie; Picart, Sébastien; Belin, Renaud C; Lebreton, Florent; Martin, Philippe M; Dardenne, Kathy; Rothe, Jörg; Neuville, Daniel R; Delahaye, Thibaud; Ayral, André

2015-04-14

Transmutation of americium in heterogeneous mode through the use of U1-xAmxO2±δ ceramic pellets, also known as Americium Bearing Blankets (AmBB), has become a major research axis. Nevertheless, in order to consider future large-scale deployment, the processes involved in AmBB fabrication have to minimize fine particle dissemination, due to the presence of americium, which considerably increases the risk of contamination. New synthesis routes avoiding the use of pulverulent precursors are thus currently under development, such as the Calcined Resin Microsphere Pelletization (CRMP) process. It is based on the use of weak-acid resin (WAR) microspheres as precursors, loaded with actinide cations. After two specific calcinations under controlled atmospheres, resin microspheres are converted into oxide microspheres composed of a monophasic U1-xAmxO2±δ phase. Understanding the different mechanisms during thermal conversion, that lead to the release of organic matter and the formation of a solid solution, appear essential. By combining in situ techniques such as XRD and XAS, it has become possible to identify the key temperatures for oxide formation, and the corresponding oxidation states taken by uranium and americium during mineralization. This paper thus presents the first results on the mineralization of (U,Am) loaded resin microspheres into a solid solution, through in situ XAS analysis correlated with HT-XRD.

Monitoring of fluoride and iodide levels in drinking water using ion selective electrodes

International Nuclear Information System (INIS)

Ahmed, R.; Viqar-Un-Nisa; Hussain, M.; Tanwir, R.; Qureshi, S.A.

2004-01-01

Fluoride and iodide, the most important constituents of drinking water are essential as well as toxic depending on their levels. For their analysis in water mostly ion-selective electrodes, spectrophotometry, titrimetry and coulometry etc; have been used and literature has been briefly reviewed. Ion-selective electrodes offer an efficient method for the measurement of the two halides and were mostly used during this work. Fabrication of these electrodes is briefly described. Comparison of results obtained by ion selective electrode and coulometry is given. Recoveries of the added fluoride ions from the samples were good. A large number of water samples from Rawalpindi-Islamabad area were analyzed for fluoride and iodide. Levels of fluoride and iodide from two main water reservoirs of Rawalpindi and Islamabad are reported before and after treatment. Both surface and ground water samples were analyzed and results are compared and discussed. Some samples from northern areas were also analyzed for iodide and fluoride and compared. Intake of fluoride and iodide from water of different areas is also compared. Water samples, which caused bone deformation in certain areas in Punjab due to excess fluoride, were also analyzed for fluoride and results are presented. (author)

Stable iodide doping induced by photonic curing for carbon nanotube transparent conductive films

Science.gov (United States)

Wachi, Atsushi; Nishikawa, Hiroyuki; Zhou, Ying; Azumi, Reiko

2018-06-01

Doping has become crucial for achieving stable and high-performance conductive transparent carbon nanotube (CNT) films. In this study, we systematically investigate the doping effects of a few materials including alkali metal iodides, nonmetal iodide, and metals. We demonstrate that photonic curing can enhance the doping effects, and correspondingly improve the conductivity of CNT films, and that such iodides have better doping effects than metals. In particular, doping with a nonmetal compound (NH4I) shows the largest potential to improve the conductivity of CNT films. Typically, doping with metal iodides reduces the sheet resistance (R S) of CNT films with 70–80% optical transmittances at λ = 550 nm from 600–2400 to 250–440 Ω/square, whereas doping with NH4I reduces R S to 57 and 84 Ω/square at 74 and 84% optical transmittances, respectively. Interestingly, such a doped CNT film exhibits only a slight increase in sheet resistance under an extreme environment of high temperature (85 °C) and high relative humidity (85%) for 350 h. The results suggest that photonic-curing-induced iodide doping is a promising approach to producing high-performance conductive transparent CNT films.

Vapor pressure of selected organic iodides

Czech Academy of Sciences Publication Activity Database

Fulem, M.; Růžička, K.; Morávek, P.; Pangrác, Jiří; Hulicius, Eduard; Kozyrkin, B.; Shatunov, V.

2010-01-01

Roč. 55, č. 11 (2010), 4780-4784 ISSN 0021-9568 R&D Projects: GA ČR GA203/08/0217 Institutional research plan: CEZ:AV0Z10100521 Keywords : vapor pressure * static method * organic iodides Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.089, year : 2010

Plutonium, americium, and uranium in blow-sand mounds of safety-shot sites at the Nevada Test Site and the Tonopah Test Range

International Nuclear Information System (INIS)

Essington, E.H.; Gilbert, R.O.; Wireman, D.L.; Brady, D.N.; Fowler, E.B.

1977-01-01

Blow-sand mounds or miniature sand dunes and mounds created by burrowing activities of animals were investigated by the Nevada Applied Ecology Group (NAEG) to determine the influence of mounds on plutonium, americium, and uranium distributions and inventories in areas of the Nevada Test Site and Tonopah Test Range. Those radioactive elements were added to the environment as a result of safety experiments of nuclear devices. Two studies were conducted. The first was to estimate the vertical distribution of americium in the blow-sand mounds and in the desert pavement surrounding the mounds. The second was to estimate the amount or concentration of the radioactive materials accumulated in the mound relative to the desert pavement. Five mound types were identified in which plutonium, americium, and uranium concentrations were measured: grass, shrub, complex, animal, and diffuse. The mount top (that portion above the surrounding land surface datum), the mound bottom (that portion below the mound to a depth of 5 cm below the surrounding land surface datum), and soil from the immediate area surrounding the mound were compared separately to determine if the radioactive elements had concentrated in the mounds. Results of the studies indicate that the mounds exhibit higher concentrations of plutonium, americium, and uranium than the immediate surrounding soil. The type of mound does not appear to have influenced the amount of the radioactive material found in the mound except for the animal mounds where the burrowing activities appear to have obliterated distribution patterns

Americium-curium vitrification process development

International Nuclear Information System (INIS)

Fellinger, A.P.; Baich, M.A.; Hardy, B.J

1999-01-01

The successful demonstration of sequentially drying, calcining and vitrifying an oxalate slurry in the Drain Tube Test Stand (DTTS) vessel provided the process basis for testing on a larger scale in a cylindrical induction heated melter. A single processing issue, that of batch volume expansion, was encountered during the initial stage of testing. The increase in batch volume centered on a sintered frit cap and high temperature bubble formation. The formation of a sintered frit cap expansion was eliminated with the use of cullet. Volume expansions due to high temperature bubble formation (oxygen liberation from cerium reduction) were mitigated in the DTTS melter vessel through a vessel temperature profile that effectively separated the softening point of the glass cullet and the evolving oxygen from cerium reduction. An increased processing temperature of 1,470 C and a two hour hold time to find any remaining bubbles successfully reduced bubbles in the poured glass to an acceptable level. The success of the preliminary process demonstrations provided a workable process basis that was directly applicable to the newly installed Cylindrical Induction Melter (CIM) system, making the batch flowsheet the preferred option for vitrification of the americium-curium surrogate feed stream

Experimental and in situ investigations on americium, curium and plutonium behaviour in marine benthic species: transfer from water or sediments

International Nuclear Information System (INIS)

Miramand, P.

1984-06-01

The tranfer of transuranic elements -americium, curium and plutonium- from the sediments containing them to some marine benthic species (endofauna and epifauna) was studied with a twofold approach - laboratory and in-situ investigation. The experimental investigations, divided into three parts, made it possible to specify concentration factors (F.C.), transfer factors (F.T.) and to understand the process involved for 5 benthic species. The result were refined by an in-situ study that brought new data on the marine distribution of the transuranic elements released by the La Hague plant. Finally, the localization of americium and plutonium in the tissues and cells of these species was determined by autoradiography [fr

Accumulation of americium-241 in the biomass of aquatic plants of the Yenisei river: experimental study

International Nuclear Information System (INIS)

Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G.

2004-01-01

Due to the operation of the Mining-and-Chemical Combine (Krasnoyarsk-26), which has been manufacturing weapons-grade plutonium for several decades, the Yenisei River is contaminated with transuranic elements (including 241 Am). 241 Am was found in the riverside soil, sediment and in the biomass of aquatic plants (Bolsunovsky et al., 1999, 2002). Aquatic plants are an important link in the migration of radionuclides in an aquatic ecosystem. In laboratory experiments, we investigated accumulation of 241 Am by the submerged macrophyte from the Yenisei River: the pond weed (Elodea canadensis) and the aquatic moss (Fontinalis antipyretica), and release of 241 Am from the biomass. The content of 241 Am was measured on a Canberra (USA) gamma-spectrometer. The experiments showed that specific accumulation and concentration factors of 241 Am in the plants were in inverse proportion to their biomass. We obtained new data on release of 241 Am from the biomass of macrophyte. Americium-241 was more firmly fixed in the biomass of the aquatic moss. In 12 months, the biomass of the aquatic moss released about 30% of the initial americium activity into the water. To compare, the biomass of the pond weed released into the water medium up to 64% of the initial 241 Am activity in 1.5 4 months. The release rate was dependent on the decomposition rate of the plant biomass. The experiments showed that submerged macrophyte of the Yenisei River can accumulate considerable activities of 241 Am and retain americium for long periods of time in biomass. (author)

21 CFR 184.1265 - Cuprous iodide.

Science.gov (United States)

2010-04-01

... the following specific limitations: Category of food Maximum treatment level in food Functional use... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cuprous iodide. 184.1265 Section 184.1265 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

Plutonium and americium in arctic waters, the North Sea and Scottish and Irish coastal zones

DEFF Research Database (Denmark)

Hallstadius, L.; Aarkrog, Asker; Dahlgaard, Henning

1986-01-01

Plutonium and americium have been measured in surface waters of the Greenland and Barents Seas and in the northern North Sea from 1980 through 1984. Measurements in water and biota, Fucus, Mytilus and Patella, were carried out in North-English and Scottish waters in 1982 and Fucus samples were co...

The behaviour under irradiation of molybdenum matrix for inert matrix fuel containing americium oxide (CerMet concept)

Energy Technology Data Exchange (ETDEWEB)

D' Agata, E., E-mail: elio.dagata@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, 1755 ZG Petten (Netherlands); Knol, S.; Fedorov, A.V. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands); Fernandez, A.; Somers, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Klaassen, F. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands)

2015-10-15

Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors or Accelerator Driven System (ADS, subcritical reactors dedicated to transmutation) of long-lived nuclides like {sup 241}Am is therefore an option for the reduction of radiotoxicity of waste packages to be stored in a repository. In order to safely burn americium in a fast reactor or ADS, it must be incorporated in a matrix that could be metallic (CerMet target) or ceramic (CerCer target). One of the most promising matrix to incorporate Am is molybdenum. In order to address the issues (swelling, stability under irradiation, gas retention and release) of using Mo as matrix to transmute Am, two irradiation experiments have been conducted recently at the High Flux Reactor (HFR) in Petten (The Netherland) namely HELIOS and BODEX. The BODEX experiment is a separate effect test, where the molybdenum behaviour is studied without the presence of fission products using {sup 10}B to “produce” helium, the HELIOS experiment included a more representative fuel target with the presence of Am and fission product. This paper covers the results of Post Irradiation Examination (PIE) of the two irradiation experiments mentioned above where molybdenum behaviour has been deeply investigated as possible matrix to transmute americium (CerMet fuel target). The behaviour of molybdenum looks satisfying at operating temperature but at high temperature (above 1000 °C) more investigation should be performed.

Tris(1,2-dimethoxyethane-κ2O,O′iodidocalcium iodide

Directory of Open Access Journals (Sweden)

Siou-Wei Ou

2012-02-01

Full Text Available In the title complex, [CaI(C4H10O23]I, the CaII atom is seven-coordinated by six O atoms from three 1,2-dimethoxyethane (DME ligands and one iodide anion in a distorted pentagonal–bipyramidal geometry. The I atom and one of the O atoms from a DME ligand lie in the axial positions while the other O atoms lie in the basal plane. The other iodide anion is outside the complex cation.

Potentiometric sensing of iodide using polymeric membranes of microwave stabilized β-AgI

International Nuclear Information System (INIS)

James, Dhanya; Rao, T. Prasada

2012-01-01

Highlights: ► Stable β-phase was obtained by post MW irradiation of AgI precipitate. ► Constructed ISEby dispersing stable β-AgI crystals in polyvinyl chloride. ► Designed iodide ISE exhibited wide linear range and fast response. ► Highly selective with selectivity factors less than 10 −6 . ► Successfully applied to natural waters, table salt and human urine samples. - Abstract: A polymer based heterogeneous ion selective electrode (ISE) membrane was fabricated for the potentiometric sensing of iodide. The sensing element used for the preparation of the ISE membrane was microwave stabilized β-AgI. Because microwave energy was found to be beneficial for causing hysteresis at the phase transition temperature of AgI, an attempt has been made to prepare stable and conductive β-AgI crystals by post microwave irradiation under high pressure. A conventionally precipitated AgI based ISE was also fabricated for comparative studies. The β-AgI based ISE could respond to a wide range of iodide concentrations (1 × 10 −8 to 1 M) within 60 s with a detection limit of 10 nM. The ISE gave stable response to iodide ions in a pH range of 2.0–8.0 and was highly selective in the presence of various interfering ions. The performance of the proposed iodide ISE in the analysis of natural and seawater samples was encouraging, and the determination of iodide in table salt and human urine samples was explained using the developed sensor.

Potentiometric determination of iodides in urine

International Nuclear Information System (INIS)

Gikolaev, B.A.; Primakova, L.N.; Rakhman'ko, E.M.

1996-01-01

Variants of potentiometric method: determination using a calibrations plot, the Gran method, and the double addition method are considered. The method of double additions of the test solution to the reference one is suggested as the most favorable method of determining iodides in urine under clinical laboratory conditions. Refs. 5, tabs. 2

Inclusion complexation of tetrabutylammonium iodide by cyclodextrins

Indian Academy of Sciences (India)

Biswajit Datta

Host-guest inclusion complex of an ionic solid (tetrabutyl ammonium iodide) with α- and β- cyclodextrin has been ... tions.2 CDs are cyclic oligomer of α-D-glucose having numerous of ... of locating at the interface of two phases (liquid–liquid.

Iodide behaviour in hard clay rocks under controlled physico-chemical conditions at different concentrations

International Nuclear Information System (INIS)

Frasca, B.; Savoye, S.; Wittebroodt, C.; Leupin, O.X.; Descostes, M.; Grenut, B.; Meier, P.; Michelot, J.L.

2010-01-01

Document available in extended abstract form only. With a half-life of 1.6 10 7 years, its high mobility and its potential to accumulate in the biosphere, iodine-129 is considered, from safety assessment calculations for radioactive waste repositories, to be one of the main radiological dose contributors. Based on the findings of previous studies, iodide, especially at low concentrations, seems to be migrating at a slower rate in clay rock than Cl-36. The cause of this retardation regarding the diffusion of iodide versus chloride is not yet understood but several hypotheses are point towards sorption on natural organic matter (NOM), pyrite or redox reactions. Oxidation of iodide would form IO 3 - which is known to have a higher sorption affinity on several soils and sediment samples than iodide. The present project aims at exploring the effect on the iodide behaviour of two parameters: (i) the initial concentration of iodide and (ii) the amount of NOM contained in the argillite samples. Such an investigation is carried out on Tournemire argillite by means of both batch and through-diffusion experiments. The main challenge is to exclude as much as possible the occurrence of any experimental artefact that could induce iodide uptake (oxygen contamination, dissolution/precipitation of carbonate phases). Regarding redox conditions and rock equilibrium, all the experiments were carried out under physico-chemical conditions as close as possible to those prevailing in field. Using a glove box with an atmosphere of N 2 /CO 2 (respectively 99.6% and 0.4%), we preserved the experiments from oxygen and maintained the calculated in-situ carbonate equilibrium. At first, four through-diffusion experiments with the non-sorbing tracers HTO and Cl-36 were performed to allow the diffusive parameters of each sample to be defined. Afterwards, iodide was injected in the diffusion cells at four different concentrations (10 -6 M to 10 -3 M). Thus, the comparison of the incoming fluxes of

Evaluation of optimal silver amount for the removal of methyl iodide on silver-impregnated adsorbents

International Nuclear Information System (INIS)

Park, G.I.; Cho, I.H.; Kim, J.H.; Oh, W.Z.

2001-01-01

The adsorption characteristics of methyl iodide generated from the simulated off-gas stream on various adsorbents such as silver-impregnated zeolite (AgX), zeocarbon and activated carbon were investigated. An extensive evaluation was made on the optimal silver impregnation amount for the removal of methyl iodide at temperatures up to 300 deg. C. The degree of adsorption efficiency of methyl iodide on silver-impregnated adsorbent is strongly dependent on impregnation amount and process temperature. A quantitative comparison of adsorption efficiencies on three adsorbents in a fixed bed was investigated. The influence of temperature, methyl iodide concentration and silver impregnation amount on the adsorption efficiency is closely related to the pore characteristics of adsorbents. It shows that the effective impregnation ratio was about 10wt%, based on the degree of silver utilization for the removal of methyl iodide. The practical applicability of silver-impregnated zeolite for the removal of radioiodine generated from the DUPIC process was consequently proposed. (author)

Explosion of cation exchange column in americium recovery service, Hanford plant, August 30, 1976

International Nuclear Information System (INIS)

1976-01-01

This document is a collection of thirty references related to the explosion of the cation exchange column in the Americium Recovery Service of the Hanford Atomic Products Operation, Richland, Washington, on August 30, 1976. Some of the documents are related to the design and safety studies, while others refer to the accident and resulting decontamination efforts, investigations, and legal consequences

Determination of iodide, iodate and organo-iodine in waters with a new total organic iodine measurement approach.

Science.gov (United States)

Gong, Tingting; Zhang, Xiangru

2013-11-01

The dissolved iodine species that dominate aquatic systems are iodide, iodate and organo-iodine. These species may undergo transformation to one another and thus affect the formation of iodinated disinfection byproducts during disinfection of drinking waters or wastewater effluents. In this study, a fast, sensitive and accurate method for determining these iodine species in waters was developed by derivatizing iodide and iodate to organic iodine and measuring organic iodine with a total organic iodine (TOI) measurement approach. Within this method, organo-iodine was determined directly by TOI measurement; iodide was oxidized by monochloramine to hypoiodous acid and then hypoiodous acid reacted with phenol to form organic iodine, which was determined by TOI measurement; iodate was reduced by ascorbic acid to iodide and then determined as iodide. The quantitation limit of organo-iodine or sum of organo-iodine and iodide or sum of organo-iodine, iodide and iodate was 5 μg/L as I for a 40 mL water sample (or 2.5 μg/L as I for an 80 mL water sample, or 1.25 μg/L as I for a 160 mL water sample). This method was successfully applied to the determination of iodide, iodate and organo-iodine in a variety of water samples, including tap water, seawater, urine and wastewater. The recoveries of iodide, iodate and organo-iodine were 91-109%, 90-108% and 91-108%, respectively. The concentrations and distributions of iodine species in different water samples were obtained and compared. Copyright © 2013 Elsevier Ltd. All rights reserved.

Behaviour of organic iodides under pwr accident conditions

International Nuclear Information System (INIS)

Alm, M.

1982-01-01

Laboratory experiments were performed to study the behaviour of radioactive methyl iodide under PWR loss-of-coolant conditions. The pressure relief equipment consisted of an autoclave for simulating the primary circuit and of an expansion vessel for simulating the conditions after a rupture in the reactor coolant system. After pressure relief, the composition of the CH 3 sup(127/131)I-containing steam-air mixture within the expansion vessel was analysed at 80 0 C over a period of 42 days. On the basis of the values measured and of data taken from the literature, both qualitative and quantitative assessments have been made as to the behaviour of radioactive methyl iodide in the event of loss-of-coolant accidents. (author)

Recovery of americium from slag and crucible wastes and its purification

International Nuclear Information System (INIS)

Michael, K.M.; Dabholkar, G.M.; Vijayan, K.; Ramamoorthy, N.; Narayanan, C.V.; Jambunathan, U.; Kapoor, S.C.

1990-01-01

A method of recovery and purification of americium-241 from slag waste streams is described. Extraction of Am from slag solution of 0.16 M HNO 3 was carried out by tri-n-butyl phosphate. After stripping with acetic acid, Am was precipitated at pH 1. This was followed by metathesis to remove Ca. Final separation of Pu from Am solution was achieved by anion exchange method using Dowex 1x4 anion exchange resin. Details of large scale recovery of Am from slag are also described. (author). 12 refs., 11 tabs., 1 fig

An Aerial Radiological Survey of the Nevada Test Site - Area 10 Corrective Action Unit 367

International Nuclear Information System (INIS)

Lyons, Craig

2010-01-01

A series of aerial radiological surveys were conducted over the Sedan, Uncle, and Ess ground zero areas in Area 10. The surveys were performed in November 2009 utilizing a large array of helicopter mounted sodium iodide detectors. The purpose of the survey was to update the previous radiological survey levels of the environment and surrounding areas of the ground zeros. Gross Counts, inferred exposure rates, man-made activity, and Americium-241 activity, as calculated from the aerial data are presented in the form of isopleth maps superimposed on imagery of the surveyed areas. In addition, spectral products are included that identify Cesium-137, Americium-241 and Cobalt-60 as the primary radionuclides present within the survey area.

Radiolysis of cesium iodide solutions at 35 and 85 deg C

International Nuclear Information System (INIS)

Lucas, M.

1981-09-01

An aqueous solution of cesium iodide was irradiated by the gamma rays from a cobalt 60 source with a dose rate of 0.4 Mrad/hr. At 35 deg C the iodide I - is oxidized in molecular iodine I 2 but at 85 deg C the iodate IO 3 - is obtained. The aim of this work is the study of aerosols behaviour released in accidental situation of a PWR in presence of steam [fr

Possibility of obtaining enriched americium-242g by the elution of recoil atoms from zeolite

Energy Technology Data Exchange (ETDEWEB)

Shafiev, A I; Vityutnev, V M; Ivanov, V M; Yakovlev, G N

1974-12-31

On the example of production the possibility of obtaining enriched actinide isotopes by the elution of recotl atoms with the use of a zeolite- americium-241 target was shown. The enrichment factor and the recoil atoms of / sup 242g/Am yield depend on preliminary target treatment and solution composition used for elution. (auth)

Fuel cycle covariance of plutonium and americium separations to repository capacity using information theoretic measures

International Nuclear Information System (INIS)

Scopatz, Anthony; Schneider, Erich; Li, Jun; Yim, Man-Sung

2011-01-01

A light water reactor, fast reactor symbiotic fuel cycle scenario was modeled and parameterized based on thirty independent inputs. Simultaneously and stochastically choosing different values for each of these inputs and performing the associated fuel cycle mass-balance calculation, the fuel cycle itself underwent Monte Carlo simulation. A novel information theoretic metric is postulated as a measure of system-wide covariance. This metric is the coefficient of variation of the set of uncertainty coefficients generated from 2D slices of a 3D contingency table. It is then applied to the fuel cycle, taking fast reactor used fuel plutonium and americium separations as independent variables and the capacity of a fully-loaded tuff repository as the response. This set of parameters is known from prior studies to have a strong covariance. When measured with all 435 other input parameters possible, the fast reactor plutonium and americium separations pair was found to be ranked the second most covariant. This verifies that the coefficient of variation metric captures the desired sensitivity of sensitivity effects in the nuclear fuel cycle. (author)

Influence of biofilms on migration of uranium, americium and europium in the environment; Einfluss von Biofilmen auf das Migrationsverhalten von Uran, Americium und Europium in der Umwelt

Energy Technology Data Exchange (ETDEWEB)

Baumann, Nils; Zirnstein, Isabel; Arnold, Thuro

2015-07-01

The report on the influence of biofilms on migration of uranium, americium and europium in the environment deals with the contamination problems of uranium mines such as SDAG WISMUT in Saxonia and Thuringia. In mine waters microorganisms form a complex microbiological biocoenosis in spite of low pH values and high heavy metal concentrations including high uranium concentrations. The analyses used microbiological methods like confocal laser scanning microscopy and molecular-biological techniques. The interactions of microorganism with fluorescent radioactive heavy metal ions were performed with TRLFS (time resolved laser-induced fluorescence spectroscopy).

Carbamazepine (Tegretol) inhibits in vivo iodide uptake and hormone synthesis in rat thyroid glands

International Nuclear Information System (INIS)

Villa, S.M.; Alexander, N.M.

1987-01-01

Decreased serum concentrations of T3 and T4 occur in patients treated with the anticonvulsant drug carbamazepine (CBZ), but with rare exception, these patients remain euthyroid. The mechanism that accounts for diminished hormone levels is unknown, and our objective was to study the direct effect of CBZ on iodide uptake and hormone synthesis in thyroid glands of CBZ-treated and pair-fed control rats. Chronic ingestion (per os) of CBZ in male rats reduced the four hour thyroid 131I-iodide uptake by approximately 60%. This inhibition occurred after the animals had received sufficient CBZ to attain plasma CBZ concentrations of 0.8 microgram/ml. Continued treatment with CBZ ranging from 560 to 800 mg/kg/day for 14 days did not result in further inhibition of iodide uptake even though the plasma CBZ concentrations had increased 6-20 fold. No inhibition of iodide uptake was apparent when the animals initially received CBZ ranging from 40 to 152 mg/kg body weight for 22 days when there were no detectable levels of plasma CBZ. Overall growth rates of CBZ-treated rats were slightly (6-10%) less than the pair-fed control animals. Plasma T4 concentrations were reduced by 18% (p less than 0.05) in the CBZ-fed animals, while T3 concentrations were diminished by 53% (p less than 0.01). CBZ appeared to alter thyroidal iodide transport because the thyroid:plasma iodide ratios were decreased by 26% in the drug-treated rats. The distribution of radioiodine in thyroidal iodoamino acids was essentially the same in both groups of rats but the absolute quantities of radioiodine were more than 2.5 times greater in the control rats. CBZ failed to inhibit peroxidase-catalyzed iodide and guaiacol oxidation in vitro

One column method to prepare 11C-labelled methyl iodide

International Nuclear Information System (INIS)

Kovacs, Z.; Priboczki, E.

1999-01-01

A new method in which the [ 11 C]methyl iodide is prepared on one alumina column is presented. A high specific surface alumina column, previously impregnated with lithium aluminium hydride solution, was used for direct trapping from the target gas and reduction into radiocomplex. The complex was then reacted on this column with HI to form [ 11 C]methyl iodide. The use of one alumina column, instead of a freezing trap, reaction vessel and separate unit for iodination, simplifies the apparatus, shortens the synthesis time and is well suitable for automation. (K.A.)

Iodide-trapping defect of the thyroid

International Nuclear Information System (INIS)

Pannall, P.R.; Steyn, A.F.; Van Reenen, O.

1978-01-01

We describe a grossly hypothyroid 50-year-old woman, mentally retarded since birth. On the basis of her history of recurrent goitre, absence of 131 I neck uptake and a low saliva/plasma 131 I ratio, congenital hypothyroidism due to a defect of the iodide-trapping mechanism was diagnosed. Other family members studied did not have the defect

Accumulation of americium-241 in the biomass of aquatic plants of the Yenisei river: experimental study

Energy Technology Data Exchange (ETDEWEB)

Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk (Russian Federation)

2004-07-01

Due to the operation of the Mining-and-Chemical Combine (Krasnoyarsk-26), which has been manufacturing weapons-grade plutonium for several decades, the Yenisei River is contaminated with transuranic elements (including {sup 241}Am). {sup 241}Am was found in the riverside soil, sediment and in the biomass of aquatic plants (Bolsunovsky et al., 1999, 2002). Aquatic plants are an important link in the migration of radionuclides in an aquatic ecosystem. In laboratory experiments, we investigated accumulation of {sup 241}Am by the submerged macrophyte from the Yenisei River: the pond weed (Elodea canadensis) and the aquatic moss (Fontinalis antipyretica), and release of {sup 241}Am from the biomass. The content of {sup 241}Am was measured on a Canberra (USA) gamma-spectrometer. The experiments showed that specific accumulation and concentration factors of {sup 241}Am in the plants were in inverse proportion to their biomass. We obtained new data on release of {sup 241}Am from the biomass of macrophyte. Americium-241 was more firmly fixed in the biomass of the aquatic moss. In 12 months, the biomass of the aquatic moss released about 30% of the initial americium activity into the water. To compare, the biomass of the pond weed released into the water medium up to 64% of the initial {sup 241}Am activity in 1.5 4 months. The release rate was dependent on the decomposition rate of the plant biomass. The experiments showed that submerged macrophyte of the Yenisei River can accumulate considerable activities of {sup 241}Am and retain americium for long periods of time in biomass. (author)

Electrosorption of tetraalkylammonium ions on silver iodide

NARCIS (Netherlands)

Keizer, de A.

1981-01-01

The object of the present investigations was to study the ef fect of the adsorption of charged organic ions on electrically charged, solid-liquid interfaces. To that end, symmetrical quater nary ammonium ions were adsorbed on a silver iodide-electrolyte interface at various

21 CFR 520.763b - Dithiazanine iodide powder.

Science.gov (United States)

2010-04-01

... therapy for adult worms. (2) The drug is contraindicated in animals sensitive to dithiazanine iodide and...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763b Dithiazanine...

Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

Energy Technology Data Exchange (ETDEWEB)

Holm, J.; Glaenneskog, H.; Ekberg, C. (Chalmers Univ. of Technology (Sweden)); Kaerkelae, T.; Auvinen, A. (VTT Technical Research Centre of Finland (Finland))

2010-05-15

An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment was started. During 2009, oxidation of iodine, especially organic iodine, was studied within the NROI project. The chemistry of organic iodine in the gas phase is still one of the greatest remaining uncertainties concerning iodine behaviour during a severe accident. During the first year of the NROI project the oxidation of elemental iodine, I2, with ozone and UV-light was investigated. In this study organic iodide, in this case methyl iodide, was investigated in similar conditions as in the NROI-1 project. The experimental facility applied in this study is based on the sampling system built at VTT for the ISTP project CHIP conducted by IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UVC intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. Instant and extensive particle formation occurred when methyl iodide was transported through a UVC radiation field and/or when ozone was present. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-150 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine

Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

International Nuclear Information System (INIS)

Holm, J.; Glaenneskog, H.; Ekberg, C.; Kaerkelae, T.; Auvinen, A.

2010-05-01

An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment was started. During 2009, oxidation of iodine, especially organic iodine, was studied within the NROI project. The chemistry of organic iodine in the gas phase is still one of the greatest remaining uncertainties concerning iodine behaviour during a severe accident. During the first year of the NROI project the oxidation of elemental iodine, I2, with ozone and UV-light was investigated. In this study organic iodide, in this case methyl iodide, was investigated in similar conditions as in the NROI-1 project. The experimental facility applied in this study is based on the sampling system built at VTT for the ISTP project CHIP conducted by IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UVC intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. Instant and extensive particle formation occurred when methyl iodide was transported through a UVC radiation field and/or when ozone was present. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-150 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine

Processes of adsorption/desorption of iodides and cadmium cations onto/from Ag(111

Directory of Open Access Journals (Sweden)

VLADIMIR D. JOVIĆ

2011-02-01

Full Text Available In this work, the adsorption/desorption processes of iodides and cadmium cations in the presence of iodides onto/from Ag(111 were investigated. It was shown that both processes were complex, characterized by several peaks on the cyclic voltammograms (CVs. By PeakFit analysis of the recorded CVs and subsequent fitting of the obtained peaks by the Frumkin adsorption isotherm, the interaction parameter (f and the Gibbs energy of adsorption (DGads for each adsorbed phase were determined. In the case of iodide adsorption, four peaks were characterized by negative values of f, indicating attractive lateral interaction between the adsorbed anions, while two of them possessed value of f < –4, indicating phase transition processes. The adsorption/desorption processes of cadmium cations (underpotential deposition – UPD of cadmium in the presence of iodide anions was characterized by two main peaks, each of them being composed of two or three peaks with negative values of f. By the analysis of charge vs. potential dependences obtained either from the CVs or current transients on potentiostatic pulses, it was concluded that adsorbed iodides did not undergo desorption during the process of Cd UPD, but became replaced by Cd ad-atoms and remained adsorbed on top of a Cd layer and/or in between Cd the ad-atoms.

Citric complexes, neodymium citrate and americium citrate

International Nuclear Information System (INIS)

Bouhlassa, Saidati.

1981-06-01

The behaviour of neodymium and americium has been studied in citric aqueous medium by two methods: solvent extraction of elements at tracer scale as chelates and by potentiometry. So range of pH and concentrations of elements and citric acid never reached before have been explored: 10 -7 -1 M, 10 -10 -3 , Csub(H3 Cit) -1 M, 1 2 O; AmCit, xH 2 O; NdCit 2 Co(NH 3 ) 6 , 8H 2 O; AmCit 2 Co(NH 3 ) 6 , xH 2 O and Nd 3 (OH) 4 (Cit) 4 NH 4 (Co(NH 3 ) 6 ) 2 , 18H 2 O. Their spectroscopic and crystallographic characteristics have been listed and studied. The nephelauxetic effect has been estimated from citric complexes as well as from citrates of these elements. The structure of the complexes in solution has been discussed on the basis of analysis of hypersensitive transition in different complexes [fr

Electrochemistry of silver iodide the capacity of the double layer at the silver iodide-water interface

NARCIS (Netherlands)

Lyklema, J.; Overbeek, J.Th.G.

1961-01-01

A method is described for obtaining differential double layer capacities on silver iodide. Especially the influence of the nature and concentration of indifferent electrolytes was investigated, viz., the nitrates of Li·, K·, Rb·, NH4·, H·, Tl·, Mg··, Ba··, Co··, Cd··, Pb··, La···, Th····, the

An experimental study of americium-241 biokinetics in the Lobster Homarus Gammarus. Analysis of the accumulation/storage and detoxification processes at the subcellular level; Etude experimentale des biocinetiques de l`americium-241 chez le homard homarus gammarus. Analyse des mecanismes d`accumulation et de detoxication au niveau subcellulaire

Energy Technology Data Exchange (ETDEWEB)

Paquet, F

1993-01-01

An experimental study of americium-241 kinetics has been conducted in the lobster Homarus gammmarus. The investigations were conducted at all the levels from the whole body to the subcellular and molecular levels. The animals were contaminated by a single or chronic ingestion of {sup 241} Am labelled mussels. Assessments of accumulation, elimination and distribution of the radionuclide were established on organisms kept in the laboratory; they made it possible to demonstrate the importance of the digestive gland in the radionuclide transfer pathways. The preliminary results led to structural then ultrastructural investigations of the digestive gland in association with radioautographic studies and cellular extractions methods. Four cellular types were demonstrated, only two of them being implied in the radionuclide retention, the former being responsible for americium intake and the latter for its long-term retention. By means of biochemical techniques, subcellular accumulation was studied and the organelles implied in the nuclide retention were specified. Finally, a method of cellular nuclei dissociation was developed; it made it possible to analyse the molecular nature of americium ligands and to demonstrate the function of the protein nuclear matrix in the nuclide retention.

Electronic and optical properties of lead iodide

DEFF Research Database (Denmark)

Ahuja, R.; Arwin, H.; Ferreira da Silva, A.

2002-01-01

The electronic properties and the optical absorption of lead iodide (PbI2) have been investigated experimentally by means of optical absorption and spectroscopic ellipsometry, and theoretically by a full-potential linear muffin-tin-orbital method. PbI2 has been recognized as a very promising...

FY-2016 Methyl Iodide Higher NOx Adsorption Test Report

Energy Technology Data Exchange (ETDEWEB)

Soelberg, Nicholas Ray [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-09-01

Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2016 under the Department of Energy (DOE) Fuel Cycle Technology (FCT) Program Offgas Sigma Team to further research and advance the technical maturity of solid sorbents for capturing iodine-129 in off-gas streams during used nuclear fuel reprocessing. Adsorption testing with higher levels of NO (approximately 3,300 ppm) and NO2 (up to about 10,000 ppm) indicate that high efficiency iodine capture by silver aerogel remains possible. Maximum iodine decontamination factors (DFs, or the ratio of iodine flowrate in the sorbent bed inlet gas compared to the iodine flowrate in the outlet gas) exceeded 3,000 until bed breakthrough rapidly decreased the DF levels to as low as about 2, when the adsorption capability was near depletion. After breakthrough, nearly all of the uncaptured iodine that remains in the bed outlet gas stream is no longer in the form of the original methyl iodide. The methyl iodide molecules are cleaved in the sorbent bed, even after iodine adsorption is no longer efficient, so that uncaptured iodine is in the form of iodine species soluble in caustic scrubber solutions, and detected and reported here as diatomic I2. The mass transfer zone depths were estimated at 8 inches, somewhat deeper than the 2-5 inch range estimated for both silver aerogels and silver zeolites in prior deep-bed tests, which had lower NOx levels. The maximum iodine adsorption capacity and silver utilization for these higher NOx tests, at about 5-15% of the original sorbent mass, and about 12-35% of the total silver, respectively, were lower than for trends from prior silver aerogel and silver zeolite tests with lower NOx levels. Additional deep-bed testing and analyses are recommended to expand the database for organic iodide adsorption and increase the technical maturity if iodine adsorption processes.

Electron stimulated reactions of methyl iodide coadsorbed with amorphous solid water

International Nuclear Information System (INIS)

Perry, C. C.; Faradzhev, N. S.; Madey, T. E.; Fairbrother, D. H.

2007-01-01

The electron stimulated reactions of methyl iodide (MeI) adsorbed on and suspended within amorphous solid water (ice) were studied using a combination of postirradiation temperature programmed desorption and reflection absorption infrared spectroscopy. For MeI adsorbed on top of amorphous solid water (ice), electron beam irradiation is responsible for both structural and chemical transformations within the overlayer. Electron stimulated reactions of MeI result principally in the formation of methyl radicals and solvated iodide anions. The cross section for electron stimulated decomposition of MeI is comparable to the gas phase value and is only weakly dependent upon the local environment. For both adsorbed MeI and suspended MeI, reactions of methyl radicals within MeI clusters lead to the formation of ethane, ethyl iodide, and diiodomethane. In contrast, reactions between the products of methyl iodide and water dissociation are responsible for the formation of methanol and carbon dioxide. Methane, formed as a result of reactions between methyl radicals and either parent MeI molecules or hydrogen atoms, is also observed. The product distribution is found to depend on the film's initial chemical composition as well as the electron fluence. Results from this study highlight the similarities in the carbon-containing products formed when monohalomethanes coadsorbed with amorphous solid water are irradiated by either electrons or photons

Separation of americium and plutonium from nuclear wastes by the TRUEX process

International Nuclear Information System (INIS)

Leonard, R.A.; Vandegrift, G.F.; Manry, C.W.

1986-01-01

Americium and plutonium can be removed from a transuranic (TRU) waste stream to <10 nCi/g by the TRUEX process. The resulting waste is nontransuranic, greatly reducing disposal costs. An overview is given of the TRUEX process and of centrifugal contactors used to implement this process. Then, a plan for the deployment of TRUEX at the Hanford Site is discussed. Finally, details are given on the proposed use of TRUEX to treat the liquid wastes from the Plutonium Finishing Plant at the Hanford Site

An iodine supplementation of tomato fruits coated with an edible film of the iodide-doped chitosan.

Science.gov (United States)

Limchoowong, Nunticha; Sricharoen, Phitchan; Techawongstien, Suchila; Chanthai, Saksit

2016-06-01

In general, the risk of numerous thyroid cancers inevitably increases among people with iodine deficiencies. An iodide-doped chitosan (CT-I) solution was prepared for dipping tomatoes to coat the fresh surface with an edible film (1.5 μm), thereby providing iodine-rich fruits for daily intake. Characterisation of the thin film was conducted by FTIR and SEM. Stability of the CT-I film was studied via water immersion at various time intervals, and no residual iodide leached out due to intrinsic interactions between the cationic amino group of chitosan and iodide ions. Moreover, the iodide supplement exhibited no effect on the antioxidant activity of tomatoes. The iodine content in the film-coated tomato was determined by ICP-OES. The tomato coating with 1.5% (w/v) CT-I contained approximately 0.4 μg iodide per gram fresh weight. In addition, the freshness and storability of iodine-doped tomatoes were also maintained for shelf-life concerns. Copyright © 2016 Elsevier Ltd. All rights reserved.

Capture of organic iodides from nuclear waste by metal-organic framework-based molecular traps.

Science.gov (United States)

Li, Baiyan; Dong, Xinglong; Wang, Hao; Ma, Dingxuan; Tan, Kui; Jensen, Stephanie; Deibert, Benjamin J; Butler, Joseph; Cure, Jeremy; Shi, Zhan; Thonhauser, Timo; Chabal, Yves J; Han, Yu; Li, Jing

2017-09-07

Effective capture of radioactive organic iodides from nuclear waste remains a significant challenge due to the drawbacks of current adsorbents such as low uptake capacity, high cost, and non-recyclability. We report here a general approach to overcome this challenge by creating radioactive organic iodide molecular traps through functionalization of metal-organic framework materials with tertiary amine-binding sites. The molecular trap exhibits a high CH 3 I saturation uptake capacity of 71 wt% at 150 °C, which is more than 340% higher than the industrial adsorbent Ag 0 @MOR under identical conditions. These functionalized metal-organic frameworks also serve as good adsorbents at low temperatures. Furthermore, the resulting adsorbent can be recycled multiple times without loss of capacity, making recyclability a reality. In combination with its chemical and thermal stability, high capture efficiency and low cost, the adsorbent demonstrates promise for industrial radioactive organic iodides capture from nuclear waste. The capture mechanism was investigated by experimental and theoretical methods.Capturing radioactive organic iodides from nuclear waste is important for safe nuclear energy usage, but remains a significant challenge. Here, Li and co-workers fabricate a stable metal-organic framework functionalized with tertiary amine groups that exhibits high capacities for radioactive organic iodides uptake.

Capture of organic iodides from nuclear waste by metal-organic framework-based molecular traps

KAUST Repository

Li, Baiyan

2017-09-01

Effective capture of radioactive organic iodides from nuclear waste remains a significant challenge due to the drawbacks of current adsorbents such as low uptake capacity, high cost, and non-recyclability. We report here a general approach to overcome this challenge by creating radioactive organic iodide molecular traps through functionalization of metal-organic framework materials with tertiary amine-binding sites. The molecular trap exhibits a high CH3I saturation uptake capacity of 71 wt% at 150 °C, which is more than 340% higher than the industrial adsorbent Ag0@MOR under identical conditions. These functionalized metal-organic frameworks also serve as good adsorbents at low temperatures. Furthermore, the resulting adsorbent can be recycled multiple times without loss of capacity, making recyclability a reality. In combination with its chemical and thermal stability, high capture efficiency and low cost, the adsorbent demonstrates promise for industrial radioactive organic iodides capture from nuclear waste. The capture mechanism was investigated by experimental and theoretical methods.Capturing radioactive organic iodides from nuclear waste is important for safe nuclear energy usage, but remains a significant challenge. Here, Li and co-workers fabricate a stable metal-organic framework functionalized with tertiary amine groups that exhibits high capacities for radioactive organic iodides uptake.

Contrasting the surface ocean distribution of bromoform and methyl iodide; implications for boundary layer physics, chemistry and climate

Energy Technology Data Exchange (ETDEWEB)

Palmer, C J, E-mail: carl.j.palmer@gmail.co [Department of Oceanography, University of Cape Town, 7701 (South Africa)

2010-08-15

Bromoform and methyl iodide are both methane-like hydrocarbons with a halogen atom replacing one or more of the hydrogen atoms. Both of these compounds occur naturally in the environment as a result of their production from seaweed and kelp. They are of interest to climate science as a result of their catalytic destruction of boundary layer ozone (a potent greenhouse gas) and, specifically for methyl iodide, the proposed role in the formation of new cloud condensation nuclei with implications for climate. In this paper, the currently available data on the distribution of bromoform and methyl iodide are analysed and contrasted to show that the concentrations of bromoform and methyl iodide do not correlate, that, in contrast to bromoform, the parameterization of sea surface methyl iodide concentrations demands only the sea surface temperature, and that the pelagic distribution of methyl iodide appears to follow the solar zenith angle. These three observations together suggest that, while the pelagic source of bromoform is mostly biogenic, the source of methyl iodide is photochemical. This has implications for the understanding of planetary boundary layer chemistry and potential organohalogen mediated feedbacks to climate.

Contrasting the surface ocean distribution of bromoform and methyl iodide; implications for boundary layer physics, chemistry and climate

International Nuclear Information System (INIS)

Palmer, C J

2010-01-01

Bromoform and methyl iodide are both methane-like hydrocarbons with a halogen atom replacing one or more of the hydrogen atoms. Both of these compounds occur naturally in the environment as a result of their production from seaweed and kelp. They are of interest to climate science as a result of their catalytic destruction of boundary layer ozone (a potent greenhouse gas) and, specifically for methyl iodide, the proposed role in the formation of new cloud condensation nuclei with implications for climate. In this paper, the currently available data on the distribution of bromoform and methyl iodide are analysed and contrasted to show that the concentrations of bromoform and methyl iodide do not correlate, that, in contrast to bromoform, the parameterization of sea surface methyl iodide concentrations demands only the sea surface temperature, and that the pelagic distribution of methyl iodide appears to follow the solar zenith angle. These three observations together suggest that, while the pelagic source of bromoform is mostly biogenic, the source of methyl iodide is photochemical. This has implications for the understanding of planetary boundary layer chemistry and potential organohalogen mediated feedbacks to climate.

Simultaneous detection of iodine and iodide on boron doped diamond electrodes.

Science.gov (United States)

Fierro, Stéphane; Comninellis, Christos; Einaga, Yasuaki

2013-01-15

Individual and simultaneous electrochemical detection of iodide and iodine has been performed via cyclic voltammetry on boron doped diamond (BDD) electrodes in a 1M NaClO(4) (pH 8) solution, representative of typical environmental water conditions. It is feasible to compute accurate calibration curve for both compounds using cyclic voltammetry measurements by determining the peak current intensities as a function of the concentration. A lower detection limit of about 20 μM was obtained for iodide and 10 μM for iodine. Based on the comparison between the peak current intensities reported during the oxidation of KI, it is probable that iodide (I(-)) is first oxidized in a single step to yield iodine (I(2)). The latter is further oxidized to obtain IO(3)(-). This technique, however, did not allow for a reasonably accurate detection of iodate (IO(3)(-)) on a BDD electrode. Copyright © 2012 Elsevier B.V. All rights reserved.

Production of a square geometry Americium standard source for use with photodiodes

Energy Technology Data Exchange (ETDEWEB)

Costa, Priscila; Geraldo, Bianca; Raele, Marcus P.; Marumo, Júlio T.; Vicente, Roberto; Zahn, Guilherme S.; Genezini, Frederico A., E-mail: priscila3.costa@usp.br, E-mail: fredzini@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

In the development of a thermal neutron detector using a square photodiode and a thin boron film, a radioactive calibration source with the same geometry was needed. An americium-243 standard source was produced by electrodeposition aiming at the calibration of a PIN-type silicon photodiode with a detection area of 10 x 10 mm{sup 2}. To produce the samples two tests were performed. In the first test, a square stainless steel plate (10 x 10 mm{sup 2}) was fixed on the surface of the conventional plate, which was removed after deposition. To reduce the loss of activity of the source, in the second test nail polish was applied on the silver plate leaving only an area of 10 x 10 mm{sup 2} without varnish coating. Once the electrodeposition process was completed, the activity concentration measurement was performed by alpha particle spectrometry. The first method presented a lower activity when compared to the total activity of Am-243 added initially. For the second method, the total activity was concentrate in the exposed square region (without nail polish). The results showed that it is possible to obtain a square geometry source; furthermore, the surrounding nail polish was not contaminated by {sup 243}Am. The comparison of these two approaches indicated that the second method was more efficient as it was possible to concentrate all the americium activity in the delimited square area. (author)

Modelling iodide – iodate speciation in atmospheric aerosol: Contributions of inorganic and organic iodine chemistry

Directory of Open Access Journals (Sweden)

S. Pechtl

2007-01-01

Full Text Available The speciation of iodine in atmospheric aerosol is currently poorly understood. Models predict negligible iodide concentrations but accumulation of iodate in aerosol, both of which is not confirmed by recent measurements. We present an updated aqueous phase iodine chemistry scheme for use in atmospheric chemistry models and discuss sensitivity studies with the marine boundary layer model MISTRA. These studies show that iodate can be reduced in acidic aerosol by inorganic reactions, i.e., iodate does not necessarily accumulate in particles. Furthermore, the transformation of particulate iodide to volatile iodine species likely has been overestimated in previous model studies due to negligence of collision-induced upper limits for the reaction rates. However, inorganic reaction cycles still do not seem to be sufficient to reproduce the observed range of iodide – iodate speciation in atmospheric aerosol. Therefore, we also investigate the effects of the recently suggested reaction of HOI with dissolved organic matter to produce iodide. If this reaction is fast enough to compete with the inorganic mechanism, it would not only directly lead to enhanced iodide concentrations but, indirectly via speed-up of the inorganic iodate reduction cycles, also to a decrease in iodate concentrations. Hence, according to our model studies, organic iodine chemistry, combined with inorganic reaction cycles, is able to reproduce observations. The presented chemistry cycles are highly dependent on pH and thus offer an explanation for the large observed variability of the iodide – iodate speciation in atmospheric aerosol.

Solvent effect on the rate and equilibrium of reaction between 10-phenylphenoxarsine and methyl iodide

International Nuclear Information System (INIS)

Gavrilov, V.I.; Gumerov, N.S.; Rakhmatullin, R.R.

1990-01-01

Effect of solvent nature on nucleophilic capacity of three-coordinated arsenic and the equilibrium state of 10-phenylphenoxarsine (PA) reaction with methyl iodide are studied. Kinetic investigations are carried out by the conductometry at 24,35,45 deg C. It is established that quaternization of PA with methyl iodide when substituting a solvent (ketone for alcohol) increases 3-14 times with simultaneous growth of the activation energy value. When transforming from aprotic solvents to protic ones PA interaction equilibrium with methyl iodide shifts to the side of arsonic salt formation

Contribution to the prediction of americium, plutonium and neptunium behaviour in the geosphere: chemical data

International Nuclear Information System (INIS)

Robouch, P.

1989-01-01

An exhaustive bibliographic review on hydrolysis of americium gives the stability constants, at zero ionic strength. No evidence of Am(OH) 4 - formation was found by solubility studies up to pH 2 (CO 3 ) 3 characterised by its X-ray diffraction pattern is studied at a high ionic strength. All the published results on Am in carbonate media are reinterpreted using these stability constants (Am-OH-CO 3 complexes are not needed). No evidence of Am(CO 3 ) 4 5- formation was found by spectrophotometry up to 3M. Literature results are used to determine the formal redox potentials at pH = 9.4 and to calculate the formation constants, at zero ionic strength. The formation of complexes between americium and humic materials (purified fulvic and humic acids) has been studied by a spectrophotometric technique. The results are interpreted by the formation of a 1:1 complexe. Solubility of the solid PuO 2 (CO 3 ) is measured in bicarbonate media at high ionic strength, to obtain the solubility product and formation constants of the PuO 2 (CO 3 ) i 2-2i complexes [fr

Measurements of α-emitting plutonium and americium in the intertidal sands of west Cumbria, UK

International Nuclear Information System (INIS)

Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.W.; Strange, L.P.; Burton, P.J.

1990-01-01

Samples of surface sand and sand cores were collected from intertidal regions of west Cumbria between Silloth and Walney Island (including the Duddon Estuary) between 1982 and 1984 and analysed for 238 Pu, 239+240 Pu and 241 Am. Generally, more than 95% of the α-emitting transuranic nuclides were associated with the sand and less than 5% with entrained silt. The greatest concentrations of both plutonium and americium were found at Braystones. Concentrations declined with distance from the Sellafield Works. The largest actinide deposits occurred at Drigg (320 and 720 kBq m -2 of 239+240 Pu and 241 Am respectively). The integrated deposits in intertidal sand between Silloth and Walney Island were about 4.2 and 7.0 TBq respectively, which represent about 1% of the total α-emitting activity discharged to sea from Sellafield Works up to 1982. The corresponding value for the Duddon Estuary is about 0.3%. Only on beaches close to Sellafield did levels of man-made α-emitters exceed those of natural α-emitting nuclides. The radiological consequences of the intertidal inventory of plutonium and americium are shown to be very small and much less than from the seafood pathway. (author)

Elimination of americium-241 after a case of accidental inhalation

International Nuclear Information System (INIS)

Edvardsson, K.A.; Lindgren, L.

1976-01-01

In handling a 241 Am source one person received an internal contamination of about 140 nCi of americium oxide, which was deposited in the lung region. Elimination of the activity was followed for more than 3 months by external gamma counting and excreta analyses. During the first week after the inhalation about 80% of the total intake was eliminated with an effective half-life of less than 2 days. The remaining activity, deposited in the lung region, was eliminated with an effective half-life of about 17 days. About 15% of the activity eliminated from the lung region from the 10th to the 50th day was eliminated in the faeces. (author)

Synthesis and evaluation of iodide uptake inhibitors in thyroid gland

International Nuclear Information System (INIS)

Lacotte, Pierre

2012-01-01

This work was intended to discover small organic molecules acting as iodide uptake inhibitors in thyroid cells. These compounds can indeed be derivatized into biochemical probes for further characterization of proteins involved in iodide transport mechanisms. On the long term, these inhibitors also appear as attractive drug candidates for treatment of thyroid pathologies or radioprotection against iodine isotopes. A similar strategy was adopted for both of the two inhibitor families. First, we synthesized a chemical library of around 100 analogues; we measured their IC50 against iodide uptake in FRTL-5 cells to get structure-activity relationships. Absolute configuration of stereo-genic centers was also investigated, and a preferential stereochemistry was found to be responsible for activity. From this basis, around twenty 'second-generation' analogues were synthesized by combining fragments contributing to biological activity. Biological evaluation indicated that nine were very potent inhibitors, with IC50 ≤ 6 nM and satisfying physicochemical properties required for drug candidates. Finally, one photoactivatable biotinylated probe was developed in each family and used for photoaffinity labeling. Several specifically labeled proteins are still under identification and constitute new potential therapeutic targets. (author)

The method of determination of micro quantities of labelled iodide in Na125 I carrier free solution

International Nuclear Information System (INIS)

Kholbaev, A.Kh.; Shilin, E.A.

1996-01-01

The analytical method was elaborated with the purpose to increase detection limit and radiation safety of labelled iodide determination. The method includes oxidation of iodide by iodate in diluted sulphur acid solution with molar concentration 0,03-0,04/moles/litre at molar ratio of iodide to iodate I - :IO - 3 1:12,5. The extraction of I 2 produced is done by toluene. (author)

Study on the Electrochemical Behavior of Iodide at Platinum Electrode in Potassium Chlorate Solution

Energy Technology Data Exchange (ETDEWEB)

Jung, Sang Hyuk; Yeon, Jei Won; Song, Kyu Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

Radioactive iodine-131, is one of the most hazardous fission products which could be released from fuels of nuclear reactors during the severe accident of nuclear power plants. Due to its high radioactivity, high fission yield (2.8%) and hazardous biological effects, the behavior of iodine has been taken interests in many research groups. Iodine is known to be released from the fuels as a cesium iodide form, CsI. And, as nuclear fuels are mostly placed in the water pool, it is easily dissolved in the water after released from the fuels. In water, iodide anion could be oxidized into molecular iodine. As the molecular iodine is a volatile species and the oxidizing rate is affected by many environmental facts such as pH, radiolysis products and temperature, the oxidation reaction of the iodide ion has been considered as an important chemical reaction related to the severe accident of nuclear power plants In present work, the electrochemical behavior of iodide anion was observed by using cyclic voltammetric technique in potassium chlorate solutions. We observed two different oxidation waves in the oxidation potential region. From the comparison with the previous reported results, one is regarded as the oxidation of iodide into molecular iodine. The other is evaluated to be the formation of high-valent iodine-containing compounds

Gamma-ray radiolysis of methyl iodide in air, in presence of water vapor

International Nuclear Information System (INIS)

Aubert, F.

2002-03-01

This work aims at modelling the processes involved in gamma-radiolysis of methyl iodide diluted in air in presence of steam. It is to determine quantitative and qualitative information, to quantify the importance of the organic iodides destruction in case of a nuclear reactor accident. The main data for radiochemistry and iodine compounds (I x O y and INO x ) formation were reviewed and analysed. Literature data about air products radiolysis reactivity towards I 2 and CH 3 I were used to develop a mechanistic model for methyl iodide destruction in the gas phase under gamma irradiation. An ab initio study was realised for a better understanding of atomic nitrogen ( 4 S and 2 D) reactivity towards CH 3 I. The model was tested on the available experimental data and constitute a way to investigate the main processus involved in methyl iodide destruction. For the low CH 3 I concentrations, about 10 -7 - 10 -8 mol.dm -3 , N and e - are mainly responsible for the destruction. I 2 O 4 (highest iodine oxide in the model) and IONO 2 are the main resulting iodinated' compounds. (author)

A portable multi-syringe flow system for spectrofluorimetric determination of iodide in seawater.

Science.gov (United States)

Frizzarin, Rejane M; Aguado, Enrique; Portugal, Lindomar A; Moreno, Daniel; Estela, José M; Rocha, Fábio R P; Cerdà, Victor

2015-11-01

A miniaturized analyzer encompassing a poly(methyl methacrylate) chip with integrated spectrofluorimetric detection and solutions propelling by a multi-syringe module is proposed. Iodide was determined through its catalytic effect on the reaction between Ce(IV) and As(III). Matrix isopotential synchronous fluorescence was explored to set the excitation and emission wavelengths. A two-level full factorial design allowed to evaluate the significance of variables (Ce(IV), As(III) and H2SO4 concentrations) and their interaction effects in the experimental domain. A Doehlert Matrix was applied to identify the critical values. The optimized procedure showed a linear response from 1 to 100 μg L(-1) (S=53.7+2.61C, in which S is the net fluorescence and C is iodide concentration in μg L(-1)). Detection limit, coefficient of variation (n=6) and sampling rate were estimated at 0.3 μg L(-1), 0.8% and 20 h(-1), respectively. Recoveries within 90-117% were estimated for iodide spiked to seawater samples. The proposed procedure stands out because of the portability, robustness, and simplicity for in-field analysis of iodide in seawater. Copyright © 2015 Elsevier B.V. All rights reserved.

TRIPLICATE SODIUM IODIDE GAMMA RAY MONITORS FOR THE SMALL COLUMN ION EXCHANGE PROGRAM

Energy Technology Data Exchange (ETDEWEB)

Couture, A.

2011-09-20

This technical report contains recommendations from the Analytical Development (AD) organization of the Savannah River National Laboratory (SRNL) for a system of triplicate Sodium Iodide (NaI) detectors to be used to monitor Cesium-137 ({sup 137}Cs) content of the Decontaminated Salt Solution (DSS) output of the Small Column Ion Exchange (SCIX) process. These detectors need to be gain stabilized with respect to temperature shifts since they will be installed on top of Tank 41 at the Savannah River Site (SRS). This will be accomplished using NaI crystals doped with the alpha-emitting isotope, Americium-241({sup 241}Am). Two energy regions of the detector output will be monitored using single-channel analyzers (SCAs), the {sup 137}Cs full-energy {gamma}-ray peak and the {sup 241}Am alpha peak. The count rate in the gamma peak region will be proportional to the {sup 137}Cs content in the DSS output. The constant rate of alpha decay in the NaI crystal will be monitored and used as feedback to adjust the high voltage supply to the detector in response to temperature variation. An analysis of theoretical {sup 137}Cs breakthrough curves was used to estimate the gamma activity expected in the DSS output during a single iteration of the process. Count rates arising from the DSS and background sources were predicted using Microshield modeling software. The current plan for shielding the detectors within an enclosure with four-inch thick steel walls should allow the detectors to operate with the sensitivity required to perform these measurements. Calibration, testing, and maintenance requirements for the detector system are outlined as well. The purpose of SCIX is to remove and concentrate high-level radioisotopes from SRS salt waste resulting in two waste streams. The concentrated high-level waste containing {sup 137}Cs will be sent to the Defense Waste Processing Facility (DWPF) for vitrification and the low-level DSS will be sent to the Saltstone Production Facility (SPF

Triplicate Sodium Iodide Gamma Ray Monitors For The Small Column Ion Exchange Program

International Nuclear Information System (INIS)

Couture, A.

2011-01-01

This technical report contains recommendations from the Analytical Development (AD) organization of the Savannah River National Laboratory (SRNL) for a system of triplicate Sodium Iodide (NaI) detectors to be used to monitor Cesium-137 ( 137 Cs) content of the Decontaminated Salt Solution (DSS) output of the Small Column Ion Exchange (SCIX) process. These detectors need to be gain stabilized with respect to temperature shifts since they will be installed on top of Tank 41 at the Savannah River Site (SRS). This will be accomplished using NaI crystals doped with the alpha-emitting isotope, Americium-241( 241 Am). Two energy regions of the detector output will be monitored using single-channel analyzers (SCAs), the 137 Cs full-energy γ-ray peak and the 241 Am alpha peak. The count rate in the gamma peak region will be proportional to the 137 Cs content in the DSS output. The constant rate of alpha decay in the NaI crystal will be monitored and used as feedback to adjust the high voltage supply to the detector in response to temperature variation. An analysis of theoretical 137 Cs breakthrough curves was used to estimate the gamma activity expected in the DSS output during a single iteration of the process. Count rates arising from the DSS and background sources were predicted using Microshield modeling software. The current plan for shielding the detectors within an enclosure with four-inch thick steel walls should allow the detectors to operate with the sensitivity required to perform these measurements. Calibration, testing, and maintenance requirements for the detector system are outlined as well. The purpose of SCIX is to remove and concentrate high-level radioisotopes from SRS salt waste resulting in two waste streams. The concentrated high-level waste containing 137 Cs will be sent to the Defense Waste Processing Facility (DWPF) for vitrification and the low-level DSS will be sent to the Saltstone Production Facility (SPF) to be incorporated into grout.

Effect of iodide on glucose oxidation and 32P incorporation into phospholipids stimulated by different agents in dog thyroid slices

International Nuclear Information System (INIS)

Tseng, F.Y.; Rani, C.S.; Field, J.B.

1989-01-01

Since iodide (I-) inhibits TSH stimulation of cAMP formation, which mediates most of the effects of the hormone, it has been assumed that this accounts for the inhibitory action of iodide on the thyroid. However, TSH stimulation of 32P incorporation into phospholipids and stimulation of thyroid metabolism by other agonists, such as carbachol, phorbol esters, and ionophore A23187, is not cAMP mediated. The present studies examined the effect of iodide on stimulation of glucose oxidation and 32P incorporation into phospholipids by TSH and other agonists to determine if the inhibition of cAMP formation was responsible for the action of iodide. Preincubation of dog thyroid slices for 1 h with iodide (10(-4) M) inhibited TSH-, (Bu)2cAMP-, carbachol-, methylene blue-, 12-O-tetradecanoyl phorbol-13-acetate-, ionophore A23187-, prostaglandin E1-, and cholera toxin-stimulated glucose oxidation. I- also inhibited the stimulation by TSH, 12-O-tetradecanoyl phorbol-13-acetate, carbachol, and ionophore A23187 of 32P incorporation into phospholipids. The inhibition was similar whether iodide was added 2 h before or simultaneously with the agonist. I- itself sometimes stimulated basal glucose oxidation, but had no effect on basal 32P incorporation into phospholipids. The effects of iodide on basal and agonist-stimulated thyroid metabolism were blocked by methimazole (10(-3) M). When dog thyroid slices were preloaded with 32PO4 or [1-14C]glucose, the iodide inhibition of agonist stimulation disappeared, suggesting that the effect of iodide involves the transport process. In conclusion, I- inhibited stimulation of glucose oxidation and 32P incorporation into phospholipids by all agonists, indicating that the effect is independent of the cAMP system and that iodide autoregulation does not only involve this system. Oxidation and organification of iodide are necessary for the inhibition

3.2. Antibacterial activity of ethynyl-piperidol polymers and their three-iodides

International Nuclear Information System (INIS)

Khalikov, D.Kh.

2012-01-01

The antibacterial activity of ethynyl-piperidol polymers and their three-iodides was studied. The antibacterial films based on iodine with copolymer N-vinyl pyrrolidone, methylmethacrylate and butyl acrylate were obtained. It was found that samples containing 9-10% of iodine in copolymer have the antiseptic properties. The antibacterial properties of three-iodides grafted nitrogen containing polymers with cellulose fibrous materials were considered. The membrane-active properties of homo- and copolymers of ethynyl piperidol derivatives were considered as well.

SPHERE: Irradiation of sphere-pac fuel of UPuO2−x containing 3% Americium

International Nuclear Information System (INIS)

D’Agata, E.; Hania, P.R.; McGinley, J.; Somers, J.; Sciolla, C.; Baas, P.J.; Kamer, S.; Okel, R.A.F.; Bobeldijk, I.; Delage, F.; Bejaoui, S.

2014-01-01

Highlights: • SPHERE is designed to check the behaviour of MADF sphere-pac concept. • MADF sphere-pac are compared with MADF pellet. • Swelling, helium release and restructuring behaviour will be the main output of the experiment. • An experiment to check sphere-pac MABB fuel behaviour is now under design. - Abstract: Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors of long-lived nuclides like 241 Am is therefore an option for the reduction of radiotoxicity of waste packages to be stored in a repository. The SPHERE irradiation experiment is the latest of a series of European experiments on americium transmutation (e.g. EFTTRA-T4, EFTTRA-T4bis, HELIOS, MARIOS) performed in the HFR (High Flux Reactor). The SPHERE experiment is carried out in the framework of the 4-year project FAIRFUELS of the EURATOM 7th Framework Programme (FP7). During the past years of experimental works in the field of transmutation and tests of innovative nuclear fuels, the release or trapping of helium as well as helium induced fuel swelling have been shown to be the key issues for the design of Am-bearing targets. The main objective of the SPHERE experiment is to study the in-pile behaviour of fuel containing 3% of americium and to compare the behaviour of sphere-pac fuel to pellet fuel, in particular the role of microstructure and temperature on fission gas release (mainly He) and on fuel swelling. The SPHERE experiment is being irradiated since September 2013 in the HFR in Petten (The Netherlands) and is expected to be terminated in spring 2015. The experiment has been designed to last up to 18 reactor cycles (corresponding to 18 months) but may reach its target earlier. This paper discusses the rationale and objective of the SPHERE experiment and provides a general description of its design

Mechanistic aspects of ingested chlorine dioxide on thyroid function: impact of oxidants on iodide metabolism

International Nuclear Information System (INIS)

Bercz, J.P.; Jones, L.L.; Harrington, R.M.; Bawa, R.; Condie, L.

1986-01-01

Toxicological studies dealing with recent findings of health effects of drinking water disinfectants are reviewed. Experiments with monkeys and rodents indicate that the biological activity of ingested disinfectants is expressed via their chemical interaction with the mucosal epithelia, secretory products, and nutritional contents of the alimentary tract. Evidence exists that a principal partner of this redox interaction is the iodide of nutritional origin that is ubiquitous in the gastrointestinal tract. Thus the observation that subchronic exposure to chlorine dioxide (ClO 2 ) in drinking water decreases serum thyroxine levels in mammalian species can be best explained with changes produced in the chemical form of the bioavailable iodide. Ongoing and previously reported mechanistic studies indicate that oxidizing agents such as chlorine-based disinfectants oxidize the basal iodide content of the gastrointestinal tract. The resulting reactive iodine species readily attaches to organic matter by covalent bonding. Evidence suggests that the extent to which such iodinated organics are formed is proportional to the magnitude of the electromotive force and stoichiometry of the redox couple between iodide and the disinfectant. Because the extent of thyroid uptake of the bioavailable iodide does not decrease during ClO 2 ingestion, it seems that ClO 2 does not cause iodide deficiency of sufficient magnitude to account for the decease in hormonogenesis. Absorption of one or more of iodinated molecules, e.g., nutrient, hormones, or cellular constituents of the alimentary tract having thyromimetic or thyroid inhibitory properties, is a better hypothesis for the effects seen

Horizontal Ampoule Growth and Characterization of Mercuric Iodide at Controlled Gas Pressures for X-Ray and Gamma Ray Spectrometers

International Nuclear Information System (INIS)

Douglas, S.; McGregor Elsa; Ariesanti Bridget Corcoran

2004-01-01

The project developed a new method for producing high quality mercuric iodide crystals of x-ray and gamma spectrometers. Included are characterization of mercuric iodide crystal properties as a function of growth environment and fabrication and demonstration of room-temperature-operated high-resolution mercuric iodide spectrometers

Multicompartmental model for iodide, thyroxine, and triiodothyronine metabolism in normal and spontaneously hyperthyroid cats

Energy Technology Data Exchange (ETDEWEB)

Hays, M.T.; Broome, M.R.; Turrel, J.M.

1988-06-01

A comprehensive multicompartmental kinetic model was developed to account for the distribution and metabolism of simultaneously injected radioactive iodide (iodide*), T3 (T3*), and T4 (T4*) in six normal and seven spontaneously hyperthyroid cats. Data from plasma samples (analyzed by HPLC), urine, feces, and thyroid accumulation were incorporated into the model. The submodels for iodide*, T3*, and T4* all included both a fast and a slow exchange compartment connecting with the plasma compartment. The best-fit iodide* model also included a delay compartment, presumed to be pooling of gastrosalivary secretions. This delay was 62% longer in the hyperthyroid cats than in the euthyroid cats. Unexpectedly, all of the exchange parameters for both T4 and T3 were significantly slowed in hyperthyroidism, possibly because the hyperthyroid cats were older. None of the plasma equivalent volumes of the exchange compartments of iodide*, T3*, or T4* was significantly different in the hyperthyroid cats, although the plasma equivalent volume of the fast T4 exchange compartments were reduced. Secretion of recycled T4* from the thyroid into the plasma T4* compartment was essential to model fit, but its quantity could not be uniquely identified in the absence of multiple thyroid data points. Thyroid secretion of T3* was not detectable. Comparing the fast and slow compartments, there was a shift of T4* deiodination into the fast exchange compartment in hyperthyroidism. Total body mean residence times (MRTs) of iodide* and T3* were not affected by hyperthyroidism, but mean T4* MRT was decreased 23%. Total fractional T4 to T3 conversion was unchanged in hyperthyroidism, although the amount of T3 produced by this route was increased nearly 5-fold because of higher concentrations of donor stable T4.

Multicompartmental model for iodide, thyroxine, and triiodothyronine metabolism in normal and spontaneously hyperthyroid cats

International Nuclear Information System (INIS)

Hays, M.T.; Broome, M.R.; Turrel, J.M.

1988-01-01

A comprehensive multicompartmental kinetic model was developed to account for the distribution and metabolism of simultaneously injected radioactive iodide (iodide*), T3 (T3*), and T4 (T4*) in six normal and seven spontaneously hyperthyroid cats. Data from plasma samples (analyzed by HPLC), urine, feces, and thyroid accumulation were incorporated into the model. The submodels for iodide*, T3*, and T4* all included both a fast and a slow exchange compartment connecting with the plasma compartment. The best-fit iodide* model also included a delay compartment, presumed to be pooling of gastrosalivary secretions. This delay was 62% longer in the hyperthyroid cats than in the euthyroid cats. Unexpectedly, all of the exchange parameters for both T4 and T3 were significantly slowed in hyperthyroidism, possibly because the hyperthyroid cats were older. None of the plasma equivalent volumes of the exchange compartments of iodide*, T3*, or T4* was significantly different in the hyperthyroid cats, although the plasma equivalent volume of the fast T4 exchange compartments were reduced. Secretion of recycled T4* from the thyroid into the plasma T4* compartment was essential to model fit, but its quantity could not be uniquely identified in the absence of multiple thyroid data points. Thyroid secretion of T3* was not detectable. Comparing the fast and slow compartments, there was a shift of T4* deiodination into the fast exchange compartment in hyperthyroidism. Total body mean residence times (MRTs) of iodide* and T3* were not affected by hyperthyroidism, but mean T4* MRT was decreased 23%. Total fractional T4 to T3 conversion was unchanged in hyperthyroidism, although the amount of T3 produced by this route was increased nearly 5-fold because of higher concentrations of donor stable T4

Electronic properties and Compton profiles of silver iodide

Indian Academy of Sciences (India)

We have carried out an extensive study of electronic properties of silver iodide in - and -phases. The theoretical Compton profiles, energy bands, density of states and anisotropies in momentum densities are computed using density functional theories. We have also employed full-potential linearized augmented ...

Developments in mercuric iodide gamma ray imaging

Energy Technology Data Exchange (ETDEWEB)

Patt, B E; Beyerle, A G; Dolin, R C; Ortale, C [EG and G Energy Measurements, Inc., Goleta, CA (USA). Santa Barbara Operations

1989-11-01

A mercuric iodide (HgI{sub 2}) gamma ray imaging array and camera system previously described have been characterized for spatial and energy resolution. Based on these data a new camera is being developed to more fully exploit the potential of the array. Characterization results and design criteria for the new camera will be presented. (orig.).

Distribution coefficients for plutonium and americium on particulates in aquatic environments

International Nuclear Information System (INIS)

Sanchez, A.L.; Schell, W.R.; Sibley, T.H.

1982-01-01

The distribution coefficients of two transuranic elements, plutonium and americium, were measured experimentally in laboratory systems of selected freshwater, estuarine, and marine environments. Gamma-ray emitting isotopes of these radionuclides, 237 Pu and 241 Am, were significantly greater than the sorption Ksub(d) values, suggesting some irreversibility in the sorption of these radionuclides onto sediments. The effects of pH and of sediment concentration on the distribution coefficients were also investigated. There were significant changes in the Ksub(d) values as these parameters were varied. Experiments using sterilized and nonsterilized samples for some of the sediment/water systems indicate possible bacterial effects on Ksub(d) values. (author)

Synergistic Effect of Azadirachta Indica Extract and Iodide Ions on the Corrosion Inhibition of Aluminium in Acid Media

Energy Technology Data Exchange (ETDEWEB)

Arab, S. T.; Al- Turkustani, A. M.; Al- Dhahiri, R. H. [King Abd El- Aziz University, Jeddah (Saudi Arabia)

2008-06-15

The synergistic action caused by iodide ions on the corrosion inhibition of aluminium (Al) in 0.5 M HCl in the presence of Azadirachta Indica (AZI) plant extract has been investigated using potintiodynamic polarization and impedance techniques. It is found that AZI extract inhibits the corrosion of aluminium in 0.5 M HCl. The inhibition efficiency increases with the increase in AZI extract concentration, until 24% v/v of AZI extract, then Inh.% is decreased with father increase in AZI extract concentration. The adsorption of this extract in the studied concentration is found to obey Frewendlish adsorption isotherm. The addition of iodide ions enhances the inhibition efficiency to a considerable extent. The increase in Inh.% values in presence of fixed concentration of iodide ions indicates that AZI extract forms an insoluble complex at lower AZI extract concentrations by undergoing a joint adsorption. But at higher concentrations of AZI extract, competitive adsorption is found between iodide ions and the formed complex leading to less Inh.%. The Inh.% decreased in presence of iodide ions with AZI extract than in presence of AZI extract alone at all studied iodide concentrations. The synergism parameter S {sub θ} is defined and calculated from surface coverage values. This parameter in the case of AZI extract is found to be more than unity, indicating that the enhanced inhibition efficiency caused by the addition of iodide ions.

The method of determination of micro quantities of labeled iodide in carrier free Na125 solution

International Nuclear Information System (INIS)

Kholbaev, A.Kh.; Shilin, E.A.

1996-01-01

The method of determination of microquantities of labelled iodide in Na 125 carrier-free solution was elaborated. This method permits to increase the sensitivity and radiation protection of the determination of labeled iodide. It includes oxidation of iodide by iodate in diluted sulphuric acid with molar concentration 0,03-0,04 mole/l. The extraction of I 2 is made by toluene. The coloured solution is made and optical density is measured at λ=640 nm at the 10 mm optical path .(A.A.D.)

Photochemical versus biological production of methyl iodide during Meteor 55

Science.gov (United States)

Richter, U.; Wallace, D.

2003-04-01

The flux of methyl iodide from sea to air represents the largest flux of iodine from the ocean to the atmosphere. Surface water concentrations and hence fluxes are particularly high in tropical regions. This flux may be responsible for the enrichment of iodine in the marine aerosol and may contribute to important processes in the marine boundary layer, including particle formation. Methyl iodide is commonly referred to as a biogenic gas, with both macroalgae and phytoplankton identified as important sources. On the other hand experimental and field data have shown the importance of photochemical production that is not necessarily associated directly with biological activity. During the Meteor cruise 55 along 11°N in the tropical Atlantic Ocean, a series of experiments were conducted to examine the biological vs. photochemical production of methyl iodide. A total of eight separate experiments were conducted. Production of CH3I in quartz glass flasks during 24 hour incubations (dark and natural sunlight) was measured under three experimental treatments: untreated seawater, filtered seawater (0.1 um pore size filter to exclude most phytoplankton and bacteria), and seawater that was poisoned with mercuric chloride. There were two clear findings from these experiments: (1) methyl iodide production was significantly higher in all the incubations that were exposed to the light than in the dark incubations; (2) there was no significant difference between CH3I production under the three experimental treatments. These results argue very strongly for the primary importance of photochemical production of CH3I as opposed to biogenic production at least for the tropical open ocean surface waters. Further experiments are required to investigate the reactants involved, their sources, the wavelength and depth dependence of production, etc. as well as (possibly related) sink processes.

A model for additive transport in metal halide lamps containing mercury and dysprosium tri-iodide

NARCIS (Netherlands)

Beks, M.L.; Haverlag, M.; Mullen, van der J.J.A.M.

2008-01-01

The distribution of additives in a metal halide lamp is examined through numerical modelling. A model for a lamp containing sodium iodide additives has been modified to study a discharge containing dysprosium tri-iodide salts. To study the complex chemistry the method of Gibbs minimization is used

X-ray-diffraction and absorption-spectrophotometric studies of AmI/sub 3/ and AmOI

Energy Technology Data Exchange (ETDEWEB)

Haire, R.G.; Young, J.P.; Peterson, J.R.

1983-01-01

The anhydrous tri-iodides and the oxyiodide of americium were investigated by X-ray diffraction and absorption spectrophotometry. From the X-ray analysis of the tri-iodide, an orthorhombic form (PuBr/sub 3/-type structure) has been identified, which is isostructural with the lighter actinide (U-Pu) tri-iodides. A hexagonal form (BiI/sub 3/-type structure) of the tri-iodide was also found. The transition temperature for converting the orthorhombic form to the hexagonal form was established to be 400 +- 30/sup 0/C. Room temperature lattice parameters for the tri-iodide are: (1) a/sub 0/ = 0.428(4), b/sub 0/ = 1.394(1) and c/sub 0/ = 0.9974(7) nm for the orthorbombic form; and (2) a/sub 0/ = 0.7637(4) and c/sub 0/ = 2.091(2) nm for the hexagonal form. Tetragonal parameters for the oxyiodide are a/sub 0/ = 0.4010(3) and c/sub 0/ = 0.9038(6) nm. From differences in the absorption spectra of the solids at 25/sup 0/C, it is possible to differentiate between these three materials by absorption spectrophotometry.

Interaction of simple indium iodides with silver- and aluminium iodides

International Nuclear Information System (INIS)

Denisov, Yu.N.; Halova, N.S.; Fedorov, P.I.

1976-01-01

Fusibility diagrams of the systems InI-AlI 3 , InI-AgI, InI 2 -AgI, and InI 2 -AlI 3 have been studied. In the system InI-AlI 3 a compound InAlI 4 has been detected having a melting point 194 deg C and two lamination regions. In the system InI-AgI two compounds In 2 AgI 3 and InAgI 2 are formed which melt incongruently at 272 deg and 220 deg C, respectively. The formation of the compounds has been confirmed by X-ray phase analysis. Specific electroconductivity of a number of alloys of the system InI-AlI 3 has been studied. The systems of eutectic type formed by diiodide of indium with iodides of silver and aluminium have been studied by thermal and X-ray analysis and by measuring electroconductivity

Nuclear detonation, thyroid cancer and potassium iodide prophylaxis

Directory of Open Access Journals (Sweden)

Viroj Wiwanitkit

2011-01-01

Full Text Available The recent nuclear disaster at Japan has raised global concerns about effects of radioactive leakage in the environment, associated hazards, and how they can be prevented. In this article, we have tried to explain about the guidelines laid down by World Health Organization for a potassium iodide prophylaxis following a nuclear disaster, and its mechanism of action in preventing thyroid cancer. Data was collected mainly from the studies carried out during the Chernobyl disaster of Russia in 1986 and the hazardous effects especially on the thyroid gland were studied. It was seen that radioactive iodine leakage from the nuclear plants mainly affected the thyroid gland, and especially children were at a higher risk at developing the cancers. Potassium Iodide prophylaxis can be administered in order to prevent an increase in the incidence of thyroid cancers in the population of an area affected by a nuclear disaster. However, one has to be cautious while giving it, as using it without indication has its own risks.

Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We propose to utilize a new detector material, polycrystalline mercuric iodide, for background suppression by active anticoincidence shielding in gamma-ray...

Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — We utilize a new detector material, polycrystalline mercuric iodide, for background suppression by active anticoincidence shielding in gamma-ray spectrometers. Two...

Grotthuss Transport of Iodide in EMIM/I3 Ionic Crystal.

Science.gov (United States)

McDaniel, Jesse G; Yethiraj, Arun

2018-01-11

Highly ionic environments can mediate unusual chemical reactions that would otherwise be considered impossible based on chemical intuition. For example, the formation of a chemical bond between two iodide anions to form a divalent polyiodide anion is seemingly prohibited due to Coulombic repulsion. Using ab initio molecular dynamics simulations, we show that in the 1-ethyl-3-methylimidazolium (EMIM)/I 3 ionic crystal, the reactive formation of divalent and even trivalent polyiodide anions occurs with extremely small energetic barriers, due to the electrostatic field of the ionic lattice. A practical consequence of this anomalous reactivity is that iodide anions are efficiently transported within the crystal through a "Grotthuss-exchange" mechanism involving bond-breaking and forming events. We characterize two distinct transport pathways, involving both I 4 2- and I 7 3- intermediates, with fast transport of iodide resulting from the release of an I - anion on the opposite side of the intermediate species from the initial bond formation. The ordered cation arrangement in the crystal provides the necessary electrostatic screening for close approach of anions, suggesting a new counterintuitive approach to obtain high ionic conductivity. This new design principle could be used to develop better solid-state electrolytes for batteries, fuel cells, and supercapacitors.

An experimental study of americium-241 biokinetics in the Lobster Homarus Gammarus. Analysis of the accumulation/storage and detoxification processes at the subcellular level

International Nuclear Information System (INIS)

Paquet, F.

1993-01-01

An experimental study of americium-241 kinetics has been conducted in the lobster Homarus gammmarus. The investigations were conducted at all the levels from the whole body to the subcellular and molecular levels. The animals were contaminated by a single or chronic ingestion of 241 Am labelled mussels. Assessments of accumulation, elimination and distribution of the radionuclide were established on organisms kept in the laboratory; they made it possible to demonstrate the importance of the digestive gland in the radionuclide transfer pathways. The preliminary results led to structural then ultrastructural investigations of the digestive gland in association with radioautographic studies and cellular extractions methods. Four cellular types were demonstrated, only two of them being implied in the radionuclide retention, the former being responsible for americium intake and the latter for its long-term retention. By means of biochemical techniques, subcellular accumulation was studied and the organelles implied in the nuclide retention were specified. Finally, a method of cellular nuclei dissociation was developed; it made it possible to analyse the molecular nature of americium ligands and to demonstrate the function of the protein nuclear matrix in the nuclide retention

Sorption of microamount of colloidal silver iodide on hydrated iron(III) oxide

International Nuclear Information System (INIS)

Kepak, F.; Nova, J.

1975-01-01

Sorption of a microamount of colloidal silver iodide labelled with 131 I on hydrated iron/III/ oxide suspension was studied. The sorption dependence upon pH, sorbent amount, and inert electrolyte concentration has revealed that sorption of silver iodide reaches no more than 63%. The sorption lasted one hour during which the maximum value was reached. Desorption time was one hour, as well. Except for measuring the sorption dependence on pH, the sorption pH was 7.0, temperature 24+-2 0 C. (F.G.)

Potassium iodide stockpiling

International Nuclear Information System (INIS)

Krimm, R.W.

1983-01-01

After examination by the Federal Emergency Management Agency (FEMA) and other federal agencies of federal policy on the use and distribution of potassium iodide (KI) as a thyroid-blocking agent for use in off-site preparedness around commercial nuclear powerplants, FEMA believes the present shelf life of KI is too short, that the minimum ordering quantities are an obstacle to efficient procurement, and that the packaging format offered by the drug industry does not meet the wishes of state and local government officials. FEMA has asked assistance from the Food and Drug Administration in making it possible for those states wishing to satisfy appropriate requirements to do so at the minimum cost to the public. Given an appropriate packaging and drug form, there appears to be no reason for the federal government to have further involvement in the stockpiling of KI

Detection of apoptotic cells using propidium iodide staining

NARCIS (Netherlands)

Newbold, Andrea; Martin, Ben P.; Cullinane, Carleen; Bots, Michael

2014-01-01

Flow cytometry assays are often used to detect apoptotic cells in in vitro cultures. Depending on the experimental model, these assays can also be useful in evaluating apoptosis in vivo. In this protocol, we describe a propidium iodide (PI) flow cytometry assay to evaluate B-cell lymphomas that have

Effects of Potassium Iodide on Low Avid Immunological Reactions ...

African Journals Online (AJOL)

In identical test conditions keeping appropriate control, the following ... Abstract. Background: Selective in‑vivo anti‑fungal action of potassium iodide (KI) is an enigma, but .... mechanism of action of the drug against selective infections. In fact, if ...

Measurements of. alpha. -emitting plutonium and americium in the intertidal sands of west Cumbria, UK

Energy Technology Data Exchange (ETDEWEB)

Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.W.; Strange, L.P.; Burton, P.J. (UKAEA Harwell Lab. (UK). Environmental and Medical Science Div.)

1990-01-01

Samples of surface sand and sand cores were collected from intertidal regions of west Cumbria between Silloth and Walney Island (including the Duddon Estuary) between 1982 and 1984 and analysed for {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am. Generally, more than 95% of the {alpha}-emitting transuranic nuclides were associated with the sand and less than 5% with entrained silt. The greatest concentrations of both plutonium and americium were found at Braystones. Concentrations declined with distance from the Sellafield Works. The largest actinide deposits occurred at Drigg (320 and 720 kBq m{sup -2} of {sup 239+240}Pu and {sup 241}Am respectively). The integrated deposits in intertidal sand between Silloth and Walney Island were about 4.2 and 7.0 TBq respectively, which represent about 1% of the total {alpha}-emitting activity discharged to sea from Sellafield Works up to 1982. The corresponding value for the Duddon Estuary is about 0.3%. Only on beaches close to Sellafield did levels of man-made {alpha}-emitters exceed those of natural {alpha}-emitting nuclides. The radiological consequences of the intertidal inventory of plutonium and americium are shown to be very small and much less than from the seafood pathway. (author).

Alpha-lipoic acid induces sodium iodide symporter expression in TPC-1 thyroid cancer cell line

International Nuclear Information System (INIS)

Choi, Hyun-Jeung; Kim, Tae Yong; Ruiz-Llorente, Sergio; Jeon, Min Ji; Han, Ji Min; Kim, Won Gu; Shong, Young Kee; Kim, Won Bae

2012-01-01

Introduction: Patients with metastatic thyroid cancers that do not uptake iodine need effective therapeutic option. Differentiation-inducing agents have been tried to restore functional expression of sodium iodide symporter (NIS) without success. Our objective was to assess the effect of alpha-lipoic acid (ALA), known as potential antioxidant, on expression of sodium iodide symporter in thyroid cancer cells. Methods: Human thyroid cancer-derived cell lines, TPC-1, were treated with ALA, and changes in NIS mRNA and protein expression were measured. ALA's effect on NIS gene promoter was evaluated, and functional NIS expression was assessed by iodide uptake assay. Results: Treatment with ALA increased NIS mRNA expression up to ten folds of control dose-dependently after 24 h of exposure. ALA increased NIS promoter activity, and increased iodide uptake by 1.6 fold. ALA induced expression of NIS protein, but had no significant effect on the plasma membrane trafficking. ALA increased phosphorylation of CREB and nuclear translocation of pCREB, and co-treatment of ALA and trichostatin A increased iodide uptake by three folds in TPC-1 cells. Conclusions: ALA is a potential agent to increase NIS transcription in TPC-1. It could be used as an adjunctive agent to increase efficacy of radioiodine therapy if combined with a strategy to increase NIS protein trafficking to cell membrane.

Influence of biofilms on migration of uranium, americium and europium in the environment

International Nuclear Information System (INIS)

Baumann, Nils; Zirnstein, Isabel; Arnold, Thuro

2015-01-01

The report on the influence of biofilms on migration of uranium, americium and europium in the environment deals with the contamination problems of uranium mines such as SDAG WISMUT in Saxonia and Thuringia. In mine waters microorganisms form a complex microbiological biocoenosis in spite of low pH values and high heavy metal concentrations including high uranium concentrations. The analyses used microbiological methods like confocal laser scanning microscopy and molecular-biological techniques. The interactions of microorganism with fluorescent radioactive heavy metal ions were performed with TRLFS (time resolved laser-induced fluorescence spectroscopy).

Small-molecule inhibitors of sodium iodide sym-porter function

International Nuclear Information System (INIS)

Lecat-Guillet, N.; Merer, G.; Lopez, R.; Rousseau, B.; Ambroise, Y.; Pourcher, T.

2008-01-01

The Na + /l - sym-porter (NIS) mediates iodide uptake into thyroid follicular cells. Although NIS has been cloned and thoroughly studied at the molecular level, the biochemical processes involved in post-translational regulation of NIS are still unknown. The purpose of this study was to identify and characterize inhibitors of NIS function. These small organic molecules represent a starting point in the identification of pharmacological tools for the characterization of NIS trafficking and activation mechanisms. screening of a collection of 17020 drug-like compounds revealed new chemical inhibitors with potencies down to 40 nM. Fluorescence measurement of membrane potential indicates that these inhibitors do not act by disrupting the sodium gradient. They allow immediate and total iodide discharge from preloaded cells in accord with a specific modification of NIS activity, probably through distinct mechanisms. (authors)

Small-molecule inhibitors of sodium iodide sym-porter function

Energy Technology Data Exchange (ETDEWEB)

Lecat-Guillet, N.; Merer, G.; Lopez, R.; Rousseau, B.; Ambroise, Y. [CEA, DSV, Dept Bioorgan Chem et Isotop Labelling, Inst Biol et Biotechnol iBiTecS, F-91191 Gif Sur Yvette (France); Pourcher, T. [Univ Nice Sophia Antipolis, Dept Biochem et Nucl Toxicol, F-06107 Nice (France)

2008-07-01

The Na{sup +}/l{sup -} sym-porter (NIS) mediates iodide uptake into thyroid follicular cells. Although NIS has been cloned and thoroughly studied at the molecular level, the biochemical processes involved in post-translational regulation of NIS are still unknown. The purpose of this study was to identify and characterize inhibitors of NIS function. These small organic molecules represent a starting point in the identification of pharmacological tools for the characterization of NIS trafficking and activation mechanisms. screening of a collection of 17020 drug-like compounds revealed new chemical inhibitors with potencies down to 40 nM. Fluorescence measurement of membrane potential indicates that these inhibitors do not act by disrupting the sodium gradient. They allow immediate and total iodide discharge from preloaded cells in accord with a specific modification of NIS activity, probably through distinct mechanisms. (authors)

Kinetic modeling of the purging of activated carbon after short term methyl iodide loading

International Nuclear Information System (INIS)

Friedrich, V.; Lux, I.

1991-01-01

A bimolecular reaction model containing the physico-chemical parameters of the adsorption and desorption was developed earlier to describe the kinetics of methyl iodide retention by activated carbon adsorber. Both theoretical model and experimental investigations postulated constant upstream methyl iodide concentration till the maximum break-through. The work reported here includes the extension of the theoretical model to the general case when the concentration of the challenging gas may change in time. The effect of short term loading followed by purging with air, and an impulse-like increase in upstream gas concentration has been simulated. The case of short term loading and subsequent purging has been experimentally studied to validate the model. The investigations were carried out on non-impregnated activated carbon. A 4 cm deep carbon bed had been challenged by methyl iodide for 30, 90, 120 and 180 min and then purged with air, downstream methyl iodide concentration had been measured continuously. The main characteristics of the observed downstream concentration curves (time and slope of break-through, time and amplitude of maximum values) showed acceptable agreement with those predicted by the model

Extraction method for the determination of inorganic iodides in Rose Bengal labelled with 131I

International Nuclear Information System (INIS)

Lengyel, J.; Krtil, J.; Vecernik, J.

1982-01-01

An extraction method for the determination of inorganic iodides in Rose Bengal preparations labelled with 131 I is described. The method is based on the quantitative extraction of Rose Bengal into chloroform from acidic medium while the inorganic iodides remain in the aqueous phase. The method is simple, rapid, and reproducible. (author)

Uptake of Iodide From Water in Atlantic Halibut Larvae (Hippoglossus Hippoglossus L.)

DEFF Research Database (Denmark)

Moren, Mari; Sloth, Jens Jørgen; Hamre, Kristin

2008-01-01

The natural diet of marine fish larvae, copepods, contain 60-350 mg I kg(-1), while live feed used in commercial hatcheries have iodine concentrations in the range of 1 mg kg(-1). Seawater is also considered to be an important source of iodine for marine fish. The question asked in this study is ......M. The uptake was partly blocked by perchlorate (ClO3-) which is a known inhibitor of the sodium iodide symporter. This indicates that the Atlantic halibut larvae accumulate iodide through both specific and non-specific uptake pathways....

Method for removing radioactive iodine and radioactive organic iodides from effluent gases

International Nuclear Information System (INIS)

1975-01-01

A method and composition for removing radioactive and organic iodides from an 131 I-containing off-gas stream is provided. The composition for removal by adsorption is a ceramic material with a surface area of from about 5 m 2 /g to about 250 m 2 /g impregnated with a metallic salt. The method for removing the iodine or iodide is accomplished by passing the off-gas stream over the ceramic material impregnated with the metallic salt. It finds special application in air filters for nuclear power plants

Iodine from bacterial iodide oxidization by Roseovarius spp. inhibits the growth of other bacteria.

Science.gov (United States)

Zhao, Dan; Lim, Choon-Ping; Miyanaga, Kazuhiko; Tanji, Yasunori

2013-03-01

Microbial activities in brine, seawater, or estuarine mud are involved in iodine cycle. To investigate the effects of the microbiologically induced iodine on other bacteria in the environment, a total of 13 bacteria that potentially participated in the iodide-oxidizing process were isolated from water or biofilm at a location containing 131 μg ml(-1) iodide. Three distinct strains were further identified as Roseovarius spp. based on 16 S rRNA gene sequences after being distinguished by restriction fragment length polymorphism analysis. Morphological characteristics of these three Roseovarius spp. varied considerably across and within strains. Iodine production increased with Roseovarius spp. growth when cultured in Marine Broth with 200 μg ml(-1) iodide (I(-)). When 10(6) CFU/ml Escherichia coli, Pseudomonas aeruginosa, and Bacillus pumilus were exposed to various concentrations of molecular iodine (I(2)), the minimum inhibitory concentrations (MICs) were 0.5, 1.0, and 1.0 μg ml(-1), respectively. However, fivefold increases in the MICs for Roseovarius spp. were obtained. In co-cultured Roseovarius sp. IOB-7 and E. coli in Marine Broth containing iodide (I(-)), the molecular iodine concentration was estimated to be 0.76 μg ml(-1) after 24 h and less than 50 % of E. coli was viable compared to that co-cultured without iodide. The growth inhibition of E. coli was also observed in co-cultures with the two other Roseovarius spp. strains when the molecular iodine concentration was assumed to be 0.52 μg ml(-1).

Confinement Effects in Low-Dimensional Lead Iodide Perovskite Hybrids

NARCIS (Netherlands)

Kamminga, Machteld E.; Fang, Honghua; Filip, Marina R.; Giustino, Feliciano; Baas, Jacobus; Blake, Graeme R.; Loi, Maria Antonietta; Palstra, Thomas T. M.

2016-01-01

We use a layered solution crystal growth technique to synthesize high-quality single crystals of phenylalkylammonium lead iodide organic/inorganic hybrid compounds. Single-crystal X-ray diffraction reveals low-dimensional structures consisting of inorganic sheets separated by bilayers of the organic

Fast iodide-SAD phasing for high-throughput membrane protein structure determination.

Science.gov (United States)

Melnikov, Igor; Polovinkin, Vitaly; Kovalev, Kirill; Gushchin, Ivan; Shevtsov, Mikhail; Shevchenko, Vitaly; Mishin, Alexey; Alekseev, Alexey; Rodriguez-Valera, Francisco; Borshchevskiy, Valentin; Cherezov, Vadim; Leonard, Gordon A; Gordeliy, Valentin; Popov, Alexander

2017-05-01

We describe a fast, easy, and potentially universal method for the de novo solution of the crystal structures of membrane proteins via iodide-single-wavelength anomalous diffraction (I-SAD). The potential universality of the method is based on a common feature of membrane proteins-the availability at the hydrophobic-hydrophilic interface of positively charged amino acid residues with which iodide strongly interacts. We demonstrate the solution using I-SAD of four crystal structures representing different classes of membrane proteins, including a human G protein-coupled receptor (GPCR), and we show that I-SAD can be applied using data collection strategies based on either standard or serial x-ray crystallography techniques.

Transportability Class of Americium in K Basin Sludge under Ambient and Hydrothermal Processing Conditions

Energy Technology Data Exchange (ETDEWEB)

Delegard, Calvin H.; Schmitt, Bruce E.; Schmidt, Andrew J.

2006-08-01

This report establishes the technical bases for using a ''slow uptake'' instead of a ''moderate uptake'' transportability class for americium-241 (241Am) for the K Basin Sludge Treatment Project (STP) dose consequence analysis. Slow uptake classes are used for most uranium and plutonium oxides. A moderate uptake class has been used in prior STP analyses for 241Am based on the properties of separated 241Am and its associated oxide. However, when 241Am exists as an ingrown progeny (and as a small mass fraction) within plutonium mixtures, it is appropriate to assign transportability factors of the predominant plutonium mixtures (typically slow) to the Am241. It is argued that the transportability factor for 241Am in sludge likewise should be slow because it exists as a small mass fraction as the ingrown progeny within the uranium oxide in sludge. In this report, the transportability class assignment for 241Am is underpinned with radiochemical characterization data on K Basin sludge and with studies conducted with other irradiated fuel exposed to elevated temperatures and conditions similar to the STP. Key findings and conclusions from evaluation of the characterization data and published literature are summarized here. Plutonium and 241Am make up very small fractions of the uranium within the K Basin sludge matrix. Plutonium is present at about 1 atom per 500 atoms of uranium and 241Am at about 1 atom per 19000 of uranium. Plutonium and americium are found to remain with uranium in the solid phase in all of the {approx}60 samples taken and analyzed from various sources of K Basin sludge. The uranium-specific concentrations of plutonium and americium also remain approximately constant over a uranium concentration range (in the dry sludge solids) from 0.2 to 94 wt%, a factor of {approx}460. This invariability demonstrates that 241Am does not partition from the uranium or plutonium fraction for any characterized sludge matrix. Most

Methyl iodide tests on used adsorbents

International Nuclear Information System (INIS)

Kovach, J.L.

1993-01-01

This paper discusses the history of events leading to the current problems in radioiodine test conditions. These radioiodine tests are performed in the adsorbent media from both safety and non-safety related Nuclear Air Treatment Systems (NATS). The main problem addressed is that currently there are still numerous plant technical specifications for NATS which reference outdated test protocols for the surveillance testing of the radioactive methyl iodide performance of the adsorbents. Recommendations for correcting the test condition problems are presented. 7 refs

Adsorption behavior of calcined layered double hydroxides towards removal of iodide contaminants

International Nuclear Information System (INIS)

Lu Liang; He Jing; Wei Min; Evans, D.G.; Duan Xue

2005-01-01

Layered double hydroxides (LDHs), are a class of synthetic anionic clays whose structure can be described as containing brucite-like layers in which some of the divalent cations have been replaced by trivalent ions giving positively-charged sheets. This charge is balanced by intercalation of anions in the hydrated interlayer regions. The general formula is EM 2+ 1-x M 3+ x (OH) 2 ] x+ (A n- ) x/n · mH 2 O, where M 2+ and M 3+ are metal cations for example Mg 2+ and Al 3+ , that occupy octahedral sites in the hydroxide layers, A n- is an exchangeable anion, and x is the ratio M 3+ /(M 2+ + M 3+ ) and the layer charge will depend on the M 2+ /M 3+ ratio. LDHs act as sorbents of anionic species through two types of reactions, namely, anion exchange and reconstruction, which further adds the possibility of recycling and reuse. The sorption of anions from aqueous solutions by structural reconstruction of a calcined LDH is based on a very interesting property of these materials, the so-called memory effect: Calcination of LDHs produces intermediate non-stoichiometric oxides (CLDH) which undergo rehydration in aqueous medium and give back the hydroxide structure with different anions in the interlayers. Radioactive iodide is widely used in biological experiments, medical treatments and in diagnosis. During fission of uranium several iodine species are produced. All the short lived isotopes of iodine, including 1311 (half life 8.04 days), decay and only 127 I (stable) and 129 I (half life 1.59 x 10 7 years) remain as a problem. 129 I is especially considered as one of the key radionuclides that dominate the long-term radiation in underground radioactive waste stores. Iodine is one of the nuclides causing most concern among radioactive anions. Different adsorbents such as zeolites, silica gel, anion exchange paper membrane, activated carbon and activated carbon fibers, have been investigated as potential materials for elimination of iodide from liquid wastes. In this work

Impact of humic acid on the photoreductive degradation of perfluorooctane sulfonate (PFOS) by UV/Iodide process.

Science.gov (United States)

Sun, Zhuyu; Zhang, Chaojie; Chen, Pei; Zhou, Qi; Hoffmann, Michael R

2017-12-15

Iodide photolysis under UV illumination affords an effective method to produce hydrated electrons (e aq - ) in aqueous solution. Therefore, UV/Iodide photolysis can be utilized for the reductive degradation of many recalcitrant pollutants. However, the effect of naturally occurring organic matter (NOM) such as humic and fulvic acids (HA/FA), which may impact the efficiency of UV/Iodide photoreduction, is poorly understood. In this study, the UV photoreductive degradation of perfluorooctane sulfonate (PFOS) in the presence of I - and HA is studied. PFOS undergoes a relatively slow direct photoreduction in pure water, a moderate level of degradation via UV/Iodide, but a rapid degradation via UV/Iodide/HA photolysis. After 1.5 h of photolysis, 86.0% of the initial [PFOS] was degraded in the presence of both I - and HA with a corresponding defluorination ratio of 55.6%, whereas only 51.7% of PFOS was degraded with a defluorination ratio of 4.4% via UV/Iodide illumination in the absence of HA. The relative enhancement in the presence of HA in the photodegradation of PFOS can be attributed to several factors: a) HA enhances the effective generation of e aq - due to the reduction of I 2 , HOI, IO 3 - and I 3 - back to I - ; b) certain functional groups of HA (i.e., quinones) enhance the electron transfer efficiency as electron shuttles; c) a weakly-bonded association of I - and PFOS with HA increases the reaction probability; and d) absorption of UV photons by HA itself produces e aq - . The degradation and defluorination efficiency of PFOS by UV/Iodide/HA process is dependent on pH and HA concentration. As pH increases from 7.0 to 10.0, the enhancement effect of HA improves significantly. The optimal HA concentration for the degradation of 0.03 mM PFOS is 1.0 mg L -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

The sodium iodide symporter: its implications for imaging and therapy

International Nuclear Information System (INIS)

Spitzweg, C.

2007-01-01

The sodium iodide symporter (NIS) is an intrinsic plasma membrane glycoprotein that mediates the active transport of iodide in the thyroid gland and a number of extrathyroidal tissues, in particular lactating mammary gland. In addition to its key function in thyroid physiology, NIS-mediated iodide accumulation allows diagnostic thyroid scintigraphy as well as therapeutic radioiodine application in benign and malignant thyroid disease. NIS therefore represents one of the oldest targets for molecular imaging and therapy. Based on the effective administration of radioiodine that has been used for over 60 years in the management of follicular cell-derived thyroid cancer, cloning and characterization of the NIS gene has paved the way for the development of a novel cytoreductive gene therapy strategy based on targeted NIS expression in thyroidal and nonthyroidal cancer cells followed by therapeutic application of 131 I or alternative radionuclides, including 188 Re and 211 At. In addition, the possibility of direct and non-invasive imaging of functional NIS expression by 123 I- and 99m Tc-scintigraphy or 124 I-PET-imaging allows the application of NIS as a novel reporter gene. In conclusion, the dual role of NIS as diagnostic and therapeutic gene and the detection of extra-thyroidal endogenous NIS expression in breast cancer open promising perspectives in nuclear medicine and molecular oncology for diagnostic and therapeutic application of NIS outside the thyroid gland. (orig.)

High Chloride Doping Levels Stabilize the Perovskite Phase of Cesium Lead Iodide.

Science.gov (United States)

Dastidar, Subham; Egger, David A; Tan, Liang Z; Cromer, Samuel B; Dillon, Andrew D; Liu, Shi; Kronik, Leeor; Rappe, Andrew M; Fafarman, Aaron T

2016-06-08

Cesium lead iodide possesses an excellent combination of band gap and absorption coefficient for photovoltaic applications in its perovskite phase. However, this is not its equilibrium structure under ambient conditions. In air, at ambient temperature it rapidly transforms to a nonfunctional, so-called yellow phase. Here we show that chloride doping, particularly at levels near the solubility limit for chloride in a cesium lead iodide host, provides a new approach to stabilizing the functional perovskite phase. In order to achieve high doping levels, we first co-deposit colloidal nanocrystals of pure cesium lead chloride and cesium lead iodide, thereby ensuring nanometer-scale mixing even at compositions that potentially exceed the bulk miscibility of the two phases. The resulting nanocrystal solid is subsequently fused into a polycrystalline thin film by chemically induced, room-temperature sintering. Spectroscopy and X-ray diffraction indicate that the chloride is further dispersed during sintering and a polycrystalline mixed phase is formed. Using density functional theory (DFT) methods in conjunction with nudged elastic band techniques, low-energy pathways for interstitial chlorine diffusion into a majority-iodide lattice were identified, consistent with the facile diffusion and fast halide exchange reactions observed. By comparison to DFT-calculated values (with the PBE exchange-correlation functional), the relative change in band gap and the lattice contraction are shown to be consistent with a Cl/I ratio of a few percent in the mixed phase. At these incorporation levels, the half-life of the functional perovskite phase in a humid atmosphere increases by more than an order of magnitude.

Performance of iodide vapour absorption in the venturi scrubber working in self-priming mode

International Nuclear Information System (INIS)

Zhou, Yanmin; Sun, Zhongning; Gu, Haifeng; Miao, Zhuang

2016-01-01

Highlights: • The absorption performance for iodide vapour was studied under different conditions. • A mathematical model was developed to describe the iodide absorption process. • The venturi scrubber can ensure absorption efficiiency and reduce pressure loss. - Abstract: The self-priming venturi scrubber is the key component of filtered containment venting systems for the removal of radioactive products during severe accidents in nuclear power plants. This paper is focused on the absorption performance of iodide vapour in the venturi scrubber, based on experiment and mathematical calculation. The results indicate that the absorption efficiency is closely related to solution flow rate, gas flow rate and temperature, but is not sensitive to iodide inlet concentration. When solution flow rate is low, the absorption efficiency increases rapidly with increasing the solution flow rate, and when the solution is excessive, the absorption efficiency remains around 99% stably; the influence of gas flow rate on absorption efficiency is mainly reflected in the variation of gas and liquid contacting time; when the solution flow rate is low, the increase of gas flow rate will led to an obvious decrease in absorption efficiency; temperature is not important when gas flow rate in constant but becomes effective for improving the absorption efficiency when gas velocity is constant. The proposed mathematical model can predict the iodide absorption process well in the range of experimental conditions. Especially, in the condition of lower gas flow rate and higher solution flow rate, the prediction accuracy is more satisfactory; however the accuracy of prediction will decrease at higher gas flow rates and lower solution flow rates because of neglecting the transverse exchange between gas and liquid phase.

The 11C-radioisotopic study of methanol conversion on V-MCM-41; the influence of methyl iodide on the transformation

International Nuclear Information System (INIS)

Sarkadi-Priboczki, E.; Szelecsenyi, F.; Kovacs, Z.; Solmaz, A.; Balci, S.; Dogu, T.

2007-01-01

Complete text of publication follows. The MCM-41 mesoporous material has Lewis and even Bronsted acid sites to produce dimethyl ether with some hydrocarbons, while over metal modified MCM-41 mostly formaldehyde and dimethoxy methane (i.e. methylal) or methyl formate are produced. In present experiments V incorporated basically mild acid sites of MCM-41 was prepared by low temperature direct synthesis. The V-MCM-41 has enough main active Lewis sites (by V-) to form formaldehyde and also light Bronsted acid sites to let the adsorbed formaldehyde eliminate and afterwards, with methanol, to form dimethoxy methane in nonoxidative environment. This V-MCM-41 has been tested by ethanol conversion in non-oxidative environments too and diethoxy methane as main product was detected. In present work the methanol conversion, as well as the methanol co-reaction with methyl iodide are studied from the same V-MCM-41 sample using 11 C-technique. The 11 C-labelled radioactive methanol has been already applied for determination of methanol conversion rates on Cu-modified MCM-41. The V-MCM-41 was prepared by direct hydrothermal synthesis method. The adsorption rate of 11 C-methanol and, after the reaction, the desorption rate of the remaining 11 C-derivatives on catalyst were continuously detected by gamma detectors. The derivatives were analyzed by radio-gas chromatography (gas chromatograph with FID coupled on-line with a radioactivity detector). Both dimethyl ether and hydrocarbon formation are also in slight degrees according to weak Lewis and Bronsted acidities. Since the conversion was carried out without added oxygen gas, only the frame oxygen can take part into catalysis. In presence of non-radioactive methyl iodide, the radioactive methanol is converted to radioactive methyl iodide on V-MCM-41. The radio-GC analysis confirmed that the iodide induced change of the reaction performance was reversible i.e. the radioactive methyl iodide was regenerated to non-radioactive methyl

New Microporous Polymer Electrolyte Based on Polysiloxane Grafted with Imidazolium Iodide Moieties for DSSC

Directory of Open Access Journals (Sweden)

Yan Yang

2011-01-01

Full Text Available Two types of polysiloxane grafted with different ratio of imidazolium iodide moieties (IL-SiO2 have been synthesized to develop a micro-porous polymer electrolyte for quasi-solid-state dye-sensitized solar cells. The samples were characterized by 1HNMR, FT-IR spectrum, XRD, TEM and SEM, respectively. Moreover, the ionic conductivity of the electrolytes was measured by electrochemical workstation. Nanostructured polysiloxane containing imidazolium iodide showed excellent compatibility with organic solvent and polymer matrix for its ionic liquid characteristics. Increasing the proportion of imidazolium iodide moieties in polysiloxane improved the electrochemical behavior of the gel polymer electrolyte. A dye-sensitized solar cell with gel polymer electrolyte yielded an open-circuit voltage of 0.70 V, short-circuit current of 11.19 mA cm−2, and the conversion efficiency of 3.61% at 1 sun illumination.

EURADOS intercomparison on measurements and Monte Carlo modelling for the assessment of Americium in a USTUR leg phantom

International Nuclear Information System (INIS)

Lopez, M. A.; Broggio, D.; Capello, K.; Cardenas-Mendez, E.; El-Faramawy, N.; Franck, D.; James, A. C.; Kramer, G. H.; Lacerenza, G.; Lynch, T. P.; Navarro, J. F.; Navarro, T.; Perez, B.; Ruehm, W.; Tolmachev, S. Y.; Weitzenegger, E.

2011-01-01

A collaboration of the EURADOS working group on 'Internal Dosimetry' and the United States Transuranium and Uranium Registries (USTUR) has taken place to carry out an intercomparison on measurements and Monte Carlo modelling determining americium deposited in the bone of a USTUR leg phantom. Preliminary results and conclusions of this intercomparison exercise are presented here. (authors)

Standardization of a method to study the distribution of Americium in purex process

International Nuclear Information System (INIS)

Dapolikar, T.T.; Pant, D.K.; Kapur, H.N.; Kumar, Rajendra; Dubey, K.

2017-01-01

In the present work the distribution of Americium in PUREX process is investigated in various process streams. For this purpose a method has been standardized for the determination of Am in process samples. The method involves extraction of Am with associated actinides using 30% TRPO-NPH at 0.3M HNO 3 followed by selective stripping of Am from the organic phase into aqueous phase at 6M HNO 3 . The assay of aqueous phase for Am content is carried out by alpha radiometry. The investigation has revealed that 100% Am follows the HLLW route. (author)

Application of extraction chromatography to the recovery of neptunium, plutonium and americium from an industrial waste

International Nuclear Information System (INIS)

Madic, C.; Kertesz, C.; Sontag, R.; Koehly, G.

1980-01-01

A pilot scale investigation was made to evaluate the possible application of the extraction chromatographic method (LLC) to the partitioning of alpha emitters from liquid wastes containing traces of transuranium elements. A secondary purpose was to obtain pure Am0 2 , which is used to produce alpha, gamma, and neutron sources. The process developed for alpha partitioning consists essentially of the extraction of macro amounts of uranium with 30% TBP in dodecane in mixer-settlers, then coextraction of Np-237, Pu-239, and Am-241 by LLC on a macro column filled with di-n-hexyl-octoxy-methyl-phosphine oxide (POX.11) adsorbed on an inert support. In each run about 200 liters of initial waste are decontaminated of alpha emitters. The loading step is followed by selective elution of americium, neptunium, and plutonium. The americium eluate is then subjected to the following operations: (1) separation of Am from Fe and Cd by LLC on a TBP column and (2) separation of Am from lanthanide traces by LLC on an HD(DiBM)P column after oxidation of Am(III) to Am(VI). The Am in the eluate is subsequently reduced to Am(III) and precipitated as oxalate with oxalic acid. The oxalate is then filtered and calcined to yield pure AmO 2

Development of Assessment Methodology of Chemical Behavior of Volatile Iodide under Severe Accident Conditions Using EPICUR Experiments

International Nuclear Information System (INIS)

Oh, Jae Yong; Yun, Jong Il; Kim, Do Sam; Han Chul

2011-01-01

Iodine is one of the most important fission products produced in nuclear power plants. Under severe accident condition, iodine exists as a variety of species in the containment such as aqueous iodide, gaseous iodide, iodide aerosol, etc. Following release of iodine from the reactor, mostly in the form of CsI aerosol, volatile iodine can be generated from the containment sump and release to the environment. Especially, volatile organic iodide can be produced from interaction between nonvolatile iodine and organic substances present in the containment. Volatile iodide could significantly influence the alienated residents surrounding the nuclear power plant. In particular, thyroid is vulnerable to radioiodine due to its high accumulation. Therefore, it is necessary for the Korea Institute of Nuclear Safety (KINS) to develop an evaluation model which can simulate iodine behavior in the containment following a severe accident. KINS also needs to make up its methodology for radiological consequence analysis, based on MELCOR-MACCS2 calculation, by coupling a simple iodine model which can conveniently deal with organic iodides. In the long term, such a model can contribute to develop an accident source term, which is one of urgent domestic needs. Our strategy for developing the model is as follows: 1. Review the existing methodologies, 2. Develop a simple stand-alone model, 3. Validate the model using ISTP-EPICUR (Experimental Program on Iodine Chemistry under Radiation) and OECD-BIP (Behavior of Iodine Project) experimental data. In this paper we present the context of development and validation of our model named RAIM (Radio-active iodine chemistry model)

Development of Assessment Methodology of Chemical Behavior of Volatile Iodide under Severe Accident Conditions Using EPICUR Experiments

Energy Technology Data Exchange (ETDEWEB)

Oh, Jae Yong; Yun, Jong Il [KAIST, Daejeon (Korea, Republic of); Kim, Do Sam; Han Chul [Korea Institue of Nuclear Safety, Daejeon (Korea, Republic of)

2011-05-15

Iodine is one of the most important fission products produced in nuclear power plants. Under severe accident condition, iodine exists as a variety of species in the containment such as aqueous iodide, gaseous iodide, iodide aerosol, etc. Following release of iodine from the reactor, mostly in the form of CsI aerosol, volatile iodine can be generated from the containment sump and release to the environment. Especially, volatile organic iodide can be produced from interaction between nonvolatile iodine and organic substances present in the containment. Volatile iodide could significantly influence the alienated residents surrounding the nuclear power plant. In particular, thyroid is vulnerable to radioiodine due to its high accumulation. Therefore, it is necessary for the Korea Institute of Nuclear Safety (KINS) to develop an evaluation model which can simulate iodine behavior in the containment following a severe accident. KINS also needs to make up its methodology for radiological consequence analysis, based on MELCOR-MACCS2 calculation, by coupling a simple iodine model which can conveniently deal with organic iodides. In the long term, such a model can contribute to develop an accident source term, which is one of urgent domestic needs. Our strategy for developing the model is as follows: 1. Review the existing methodologies, 2. Develop a simple stand-alone model, 3. Validate the model using ISTP-EPICUR (Experimental Program on Iodine Chemistry under Radiation) and OECD-BIP (Behavior of Iodine Project) experimental data. In this paper we present the context of development and validation of our model named RAIM (Radio-active iodine chemistry model)

Tandem on-line continuous separations for atomic spectroscopic indirect analysis: iodide determination by ICP-AES

International Nuclear Information System (INIS)

Garcia, A.M.; Sanchez Uria, J.E.; Sanz-Medel, A.; Quintero Ortega, M.C.; Bautista, J.C.

1992-01-01

A sensitive and selective indirect determination of iodide by inductively coupled plasma emission spectrometry (ICP-AES) based on the principle of tandem on-line continuous separations as an alternative means of introducing samples into plasmas is proposed. Iodide is continuously extracted as an ion-pair into xylene by mixing the sample with Hg(II) and dipyridil solutions. The organic phase (containing the analyte in [Hg(Dipy) 2 ]I 2 form) is on-line continuously mixed with NaBH 4 (in DMF) and acetic acid solutions. Mercury vapour continuously generated from this organic phase is separated in a classical U-type gas-liquid separation device. The system has been optimized for the continuous extraction of KI, for the direct generation of cold mercury vapour from xylene and for the final ICP-AES determination of mercury. The optimised method has been applied to the determination of iodide (detection limit 20 ng/ml of iodide) in table salt and in synthetic samples. Very good agreement between found and certified results was observed. The usefulness and convenience of such alternative sample chemical pretreatment/presentation to the ICP is thus demonstrated for indirect determinations to be carried out by atomic spectroscopy methods. (authors)

Americium adsorption on the surface of macrophytic algae

Energy Technology Data Exchange (ETDEWEB)

Carvalho, F.P.; Fowler, S.W.

1985-01-01

Data are presented on the rates at which americium (Am) deposits upon blade surfaces of three benthic algal species (Ulva rigida, Fucus vesiculosus and Gigartina stellata) following short-term exposures (1-6 h). Am is taken up in direct proportion to the ambient radionuclide concentration in sea water. Uptake by the green alga was 3 to 5 times greater than that for the brown and red species. Experimental evidence indicated that Am accumulation is a passive process and that adsorption takes place mainly on the thin outer organic coating of the seaweed. The Am transport coefficients are quite similar to that previously found for the naturally occurring ..cap alpha..-emitter /sup 210/Po, but are an order of magnitude lower than a plutonium transport coefficient reported in the literature. Release of labelled extracellular products associated with the algal surface coating is considered to be responsible for the rapid loss of Am observed previously in macroalgae and may in fact serve as a mechanism for transferring Am to filter feeding zooplankton. (author).

Americium adsorption on the surface of macrophytic algae

International Nuclear Information System (INIS)

Carvalho, F.P.; Fowler, S.W.

1985-01-01

Data are presented on the rates at which americium (Am) deposits upon blade surfaces of three benthic algal species (Ulva rigida, Fucus vesiculosus and Gigartina stellata) following short-term exposures (1-6 h). Am is taken up in direct proportion to the ambient radionuclide concentration in sea water. Uptake by the green alga was 3 to 5 times greater than that for the brown and red species. Experimental evidence indicated that Am accumulation is a passive process and that adsorption takes place mainly on the thin outer organic coating of the seaweed. The Am transport coefficients are quite similar to that previously found for the naturally occurring α-emitter 210 Po, but are an order of magnitude lower than a plutonium transport coefficient reported in the literature. Release of labelled extracellular products associated with the algal surface coating is considered to be responsible for the rapid loss of Am observed previously in macroalgae and may in fact serve as a mechanism for transferring Am to filter feeding zooplankton. (author)

Inspection report of unauthorized possession and use of unsealed americium-241 and subsequent confiscation, J.C. Haynes Company, Newark, Ohio

International Nuclear Information System (INIS)

1985-11-01

This US Nuclear Regulatory Commission report documents the circumstances surrounding the March 26, 1985, confiscation and subsequent decontamination activities related to the use of unauthorized quantities of americium-241 at the John C. Haynes Company (licensee) of Newark, Ohio. It focuses on the period from early February to July 26, 1985. The incident started when NRC Region III recieved information that John C. Haynes possessed unauthorized quantities of americium-241 and was conducting unauthorized activities (diamond irradiation). By July 26, 1985, the decontamination activities at the licensee's laboratory were concluded. The licensee's actions with diamond irradiation resulted in contamination in restricted and unrestricted areas of the facility. The confiscation and decontamination activities required the combined efforts of NRC, Federal Bureau of Investigation, US Department of Energy, Oak Ridge Associated Universities, the State of Ohio, and the US Environmental Protection Agency. The report describes the factual information and significant findings associated with the confiscation and decontamination activities

Chemical behaviour of trivalent and pentavalent americium in saline NaCl-solutions. Studies of transferability of laboratory data to natural conditions. Interim report. Reported period: 1.2.1993-31.12.1993

International Nuclear Information System (INIS)

Runde, W.; Kim, J.I.

1994-09-01

In order to clarify the chemical behaviour of Americium in saline aqueous systems relevant for final storage this study deals with the chemical reactions of trivalent and pentavalent Americium in NaCl-solutions under the influence of radiolysis from its own alpha radiation. The focus of the study was on investigating the geologically relevant reactions, such as hydrolysis or carbonate- and chloride complexing in solid-liquid equilibriums. Comprehensive measurements on solubility and spectroscopic studies in NaCl-solutions were carried out in a CO 2 -free atmosphere and 10 -2 atm CO 2 partial pressure. Identification and characterisation of the AM (III) and AM(V) solid phases were supplemented by structural research with the chemically analogue EU (III) and Np(V) compounds. The alpha-radiation induced radiolysis in saline NaCl solutions and the redox behaviour of Americium which was influenced thereby were spectroscopically quantified. (orig.) [de

A highly sensitive PVC membrane iodide electrode based on complexes of mercury(II) as neutral carrier.

Science.gov (United States)

Chai, Y-Q; Yuan, R; Xu, L; Xu, W-J; Dai, J-Y; Jiang, F

2004-09-01

A novel solvent polymeric membrane electrode based on bis(1,3,4-thiadiazole) complexes of Hg(II) is described which has excellent selectivity and sensitivity toward iodide ion. The electrode, containing 1,4-bis(5-methyl-1,3,4-thiadiazole-2-yl-thio)butanemercury(II) [Hg(II)BMTB(NO3)4], has a Nernstian potentiometric response from 2.0 x 10(-8) to 2.0 x 10(-2) mol L(-1) with a detection limit of 8.0 x 10(-9) mol L(-1) and a slope of -59.0+/-0.5 mV/decade in 0.01 mol L(-1) phosphate buffer solution (pH 3.0, 20 degrees C). The selectivity sequence observed is iodide>bromide>thiocyanate>nitrite>nitrate>chloride>perchlorate>acetate>sulfate. The selectivity behavior is discussed in terms of the UV-Vis spectrum, and the process of transfer of iodide across the membrane interface is investigated by use of the AC impedance technique. The electrode was successfully applied to the determination of iodide in Jialing River and Spring in Jinyun Mountains, with satisfactory results.

Congenital Hypothyroidism Caused by a PAX8 Gene Mutation Manifested as Sodium/Iodide Symporter Gene Defect

Directory of Open Access Journals (Sweden)

Wakako Jo

2010-01-01

Full Text Available Loss-of-function mutations of the PAX8 gene are considered to mainly cause congenital hypothyroidism (CH due to thyroid hypoplasia. However, some patients with PAX8 mutation have demonstrated a normal-sized thyroid gland. Here we report a CH patient caused by a PAX8 mutation, which manifested as iodide transport defect (ITD. Hypothyroidism was detected by neonatal screening and L-thyroxine replacement was started immediately. Although 123I scintigraphy at 5 years of age showed that the thyroid gland was in the normal position and of small size, his iodide trapping was low. The ratio of the saliva/plasma radioactive iodide was low. He did not have goiter; however laboratory findings suggested that he had partial ITD. Gene analyses showed that the sodium/iodide symporter (NIS gene was normal; instead, a mutation in the PAX8 gene causing R31H substitution was identified. The present report demonstrates that individuals with defective PAX8 can have partial ITD, and thus genetic analysis is useful for differential diagnosis.

Determination of microamounts of potassium in sodium iodide by atomic absorption spectrometry

International Nuclear Information System (INIS)

Ogasawara, Ken; Ohta, Masatoshi; Abe, Kenzo

1980-01-01

Microdetermination of potassium in sodium iodide was developed by the standard addition method. Twenty grams of sample were dissolved in 50 ml of water in a quartz beaker. To the solution, 30 ml of concentrated hydrochloric acid and 30 ml of 30% hydrogen peroxide were added, and evaporated to dryness. By this process sodium iodide was converted into sodium chloride. The cake thus obtained was dissolved in water and diluted to exactly 200 ml. To 25 ml aliquots of the solution, the standard potassium and cesium chloride solutions were added and diluted to 50 ml with water; the concentration of potassium was 0 -- 1 mg/l and that of cesium 4 mM. These solutions were introduced into an air-propane flame and the absorbances were measured at 769.9 nm. During the conversion reaction, hydrochloric acid was completely decomposed, and remained hydrogen peroxide had no influence for absorbance, and other backgrounds were negligible. The linear calibration curve was obtained in the range 0 -- 2 mg of potassium per liter. Potassium in sodium iodide was determined by this method within the coefficient of variation of +-(20 -- 3)% in the range (1.7 -- 32.5) ppm. (author)

Comparison of two novel in-syringe dispersive liquid-liquid microextraction techniques for the determination of iodide in water samples using spectrophotometry.

Science.gov (United States)

Kaykhaii, Massoud; Sargazi, Mona

2014-01-01

Two new, rapid methodologies have been developed and applied successfully for the determination of trace levels of iodide in real water samples. Both techniques are based on a combination of in-syringe dispersive liquid-liquid microextraction (IS-DLLME) and micro-volume UV-Vis spectrophotometry. In the first technique, iodide is oxidized with nitrous acid to the colorless anion of ICl2(-) at high concentration of hydrochloric acid. Rhodamine B is added and by means of one step IS-DLLME, the ion-pair formed was extracted into toluene and measured spectrophotometrically. Acetone is used as dispersive solvent. The second method is based on the IS-DLLME microextraction of iodide as iodide/1, 10-phenanthroline-iron((II)) chelate cation ion-pair (colored) into nitrobenzene. Methanol was selected as dispersive solvent. Optimal conditions for iodide extraction were determined for both approaches. Methods are compared in terms of analytical parameters such as precision, accuracy, speed and limit of detection. Both methods were successfully applied to determining iodide in tap and river water samples. Copyright © 2013 Elsevier B.V. All rights reserved.

The distribution of plutonium-239 and americium-241 in the Syrian hamster following its intravenous administration as citrate

International Nuclear Information System (INIS)

Rodwell, P.; Stather, J.W.

1978-01-01

Actinide distribution in various tissues and the skeleton of hamsters by liquid scintillation counting or isotope dilution. For plutonium 57% of activity was concentrated in the skeleton and more than 90% in the liver and skeleton after seven days. For americium the liver retained more than 50% of total activity and 25% was excreted in urine within seven days. (U.K.)

76 FR 16770 - Petition To Suspend and Cancel All Registrations for the Soil Fumigant Iodomethane (Methyl Iodide...

Science.gov (United States)

2011-03-25

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0541; FRL-8841-7] Petition To Suspend and Cancel... Earthjustice requesting that all uses of iodomethane (methyl iodide) be suspended and cancelled. The Agency is... uses of iodomethane (methyl iodide) be suspended and cancelled. The Agency is posting this petition for...

Americium-241 in surface soil associated with the Hanford site and vicinity

International Nuclear Information System (INIS)

Price, K.R.; Gilbert, R.O.; Gano, K.A.

1981-05-01

Various kinds of surface soil samples were collected and analyzed for Americium-241 ( 241 Am) to examine the feasibility of improving soil sample data for the Hanford Surface Environmental Surveillance Program. Results do not indicate that a major improvement would occur if procedures were changed from the current practices. Conclusions from this study are somewhat tempered by the very low levels of 241 Am ( 241 Am in soil crust (0 to 1.0 cm deep) was greater than the corresponding subsurface layer (1.0 to 2.5 cm deep), and the average concentration of 241 Am in some onsite samples collected near the PUREX facility was greater than comparable samples collected 60 km upwind at an offsite location

Theoretical and experimental investigations on the behaviour of iodine during severe accidents: organic iodide, iodine/silver reaction, iodine/iron reaction. Pt. 4: organic iodide. Final report

International Nuclear Information System (INIS)

Hellmann, S.; Greger, G.U.; Funke, F.; Bleier, A.; Zeeh, W.

1995-11-01

Analysis of the consequences of severe accidents in nuclear power plants requires knowledge of the behaviour of radionuclides relevant from the radiological viewpoint. The role played by radioiodine is particularly important. In the current modelling of iodine behaviour the heterogeneous formation of organic iodide is not adequately taken into consideration owing to a lack of data or insufficient accuracy of data. This project is intended to eliminate some gaps in critical areas. This final report, part 4, describes the tests carried out in the two relevant areas - heterogeneous formation of organic coatings in the gas phase (containment atmosphere) - heterogeneous formation of organic iodide at organic coatings in aqueous phase (containment sump). Moreover, modelling suggestions how to include the resulting knowledge in the iodine accident behaviour code IMPAIR are given. (orig.) [de

Effect of radioiodine irradiation of thyroid gland in vitro with a dose of 4-5 Gy on iodide transport in thyrocytes

International Nuclear Information System (INIS)

Paster, Yi.P.

2000-01-01

We study the influence of ouabain on the basal and thyrotropin-stimulated iodide uptake in thyroid gland preliminarily irradiated by radioiodine (absorbed dose: 4-5 Gy) in vitro. Newborn pig thyroid tissue was incubated in a medium, containing 37 kBq/ml of 131-iodine (absorbed dose: 4-5 Gy), washed and achieved by collagenase dissociation. Thyrocytes were incubated with thyrotropin (100.0 mE/ml), ouabain (0.1 mol/l), and 125-iodide (0.4 kBq/ml). Then cells were washed, stored at 4 degree C for 60 days, and the 125-iodide uptake was assessed. Ouabain depressed both the basal and thyrotropin-stimulated iodide uptakes by thyrocytes in vitro. After preliminary radioiodine irradiation of the thyroid tissue (absorbed dose: 4-5 Gy), ouabain stimulated both the basal and thyrotropin-stimulated iodide uptakes by thyrocytes

Epidemiology of thyroid disorders and valuation of effects of iodide administration in the Sejny community (Poland) after Chernobyl accident

International Nuclear Information System (INIS)

Zimnicki, P.

1993-01-01

The epidemiology of thyroid disorders was studied and the effect of potassium iodide administration was evaluated in citizens of Sejny (Poland) community four years after Chernobyl accident. The endemic goiter was observed in this area. The elevated levels of anti-human thyroid membrane antibodies and anti-human thereoglobuline antibody were found in 5.5% of children that had undergone iodide administration after Chernobyl accident. It may result from iodide administration or from endemic goiter. (author). 127 refs, 9 figs, 16 tabs

Synthesis and antimicrobial activity of guanylhydrazones. Synthesis of 2-(2-methylthio-2-aminovinyl)-1-methylpyridinium iodides and 2-(2-methylthio-2-aminovinyl)-1-methylquinolinium iodides as potential radioprotective and anticancer agents

International Nuclear Information System (INIS)

Almassian, B.

1985-01-01

The finding of appreciable antileukemic activity in a series of 2-(2-methylthio-2-amino)vinyl-1-methylquinolinium iodides (Foye et al., 1980, 1983) suggested that greater basicity, as compared with the corresponding dithioacetic acids, was contributing to the increase in activity. The addition of a greater degree of basicity in the design of anticancer possibilities in this series was considered worth investigation, particularly in view of the activity of a series of bis(quanylhydrazones) synthesized at Lederle Laboratories. Accordingly, a series of guanylhydrazones of 4-pyridine-,2-pyridine- and 4-quinolinecarboxyaldehydes was synthesized for anticancer as well as antibacterial screening. Also, substitution of additional basic functions in the 2-(2-methylthio-2-amino) vinyl-1-methylquinolinium and pyridinium iodide series has been made. Appreciable antimicrobial activities have been found with both 2-pyridine and 4-quinolinealdehyde guanylhydrazones, as well as with 2-(2-methylthio-2-amino)vinyl-1-methyl-pyridinium iodides. The overall approach to the synthesis of potential anticancer agents in this project is thus to observe the effect of increasing basicity of these compounds on DNA binding and anticancer activity

Americium/Curium Melter 2A Pilot Tests

International Nuclear Information System (INIS)

Smith, M.E.; Fellinger, A.P.; Jones, T.M.; Miller, C.B.; Miller, D.H.; Snyder, T.K.; Stone, M.E.; Witt, D.C.

1998-05-01

Isotopes of americium (Am) and curium (Cm) were produced in the past at the Savannah River Site (SRS) for research, medical, and radiological applications. These highly radioactive and valuable isotopes have been stored in an SRS reprocessing facility for a number of years. Vitrification of this solution will allow the material to be more safely stored until it is transported to the DOE Oak Ridge Reservation for use in research and medical applications. To this end, the Am/Cm Melter 2A pilot system, a full-scale non- radioactive pilot plant of the system to be installed at the reprocessing facility, was designed, constructed and tested. The full- scale pilot system has a frit and aqueous feed delivery system, a dual zone bushing melter, and an off-gas treatment system. The main items which were tested included the dual zone bushing melter, the drain tube with dual heating and cooling zones, glass compositions, and the off-gas system which used for the first time a film cooler/lower melter plenum. Most of the process and equipment were proven to function properly, but several problems were found which will need further work. A system description and a discussion of test results will be given

Biosorption of americium-241 by Candida sp

International Nuclear Information System (INIS)

Luo Shunzhong; Zhang Taiming; Liu Ning; Yang Yuanyou; Jin Jiannan; Liao Jiali

2003-01-01

As an important radioisotope in nuclear industry and other fields, americium-241 is one of the most serious contamination concerns duo to its high toxicity and long half-life. In this experiment, the biosorption of 241 Am from solution by Candida sp., and the effects of various experimental conditions on the adsorption were investigated. The preliminary results showed that the adsorption of 241 Am by Candida sp. was efficient. 241 Am could be removed by Candida sp. of 0.82 g/L (dry weight) from 241 Am solutions of 5.6-111 MBq/L (44.3-877.2 μg/L)(C 0 ), with maximum adsorption rate (R) of 98% and maximum adsorption capacities (W) of 63.5 MBq/g biomass (dry weight) (501.8 μg/g). The biosorption equilibrium was achieved within 4 hour and the optimum pH was pH = 2. No significant differences on 241 Am adsorption were observed at 10 C-45 C, or in solutions containing Au 3+ or Ag + , even 1500 times or 4500 times above the 241 Am concentration, respectively. The relationship between concentrations and adsorption capacities of 241 Am indicated the biosorption process should be described by a Langmuir adsorption isotherm. (orig.)

Temperature Dependent Charge Carrier Dynamics in Formamidinium Lead Iodide Perovskite

NARCIS (Netherlands)

Gelvez Rueda, M.C.; Renaud, N.; Grozema, F.C.

2017-01-01

The fundamental opto-electronic properties of organic-inorganic hybrid perovskites are strongly affected by their structural parameters. These parameters are particularly critical in formamidinium lead iodide (FAPbI₃), in which its large structural disorder leads to a non-perovskite

Relaxation of the silver/silver iodide electrode in aqueous solution

NARCIS (Netherlands)

Peverelli, K.J.

1979-01-01

The aim of this study is to detect and characterize relaxation processes on silver/silver iodide electrodes in aqueous electrolyte solution. The information obtained is to be used for an estimation of the consequences of similar processes on colloidal AgI

Growth of mercuric iodide single crystals from dimethylsulfoxide

International Nuclear Information System (INIS)

Carlston, R.C.

1976-01-01

Dimethylsulfoxide is used as a solvent for the growth of red mercuric iodide (HgI 2 ) crystals for use in radiation detectors. The hygroscopic property of the solvent allows controlled amounts of water to enter into the solvent phase and diminish the large solubility of HgI 2 so that the precipitating solid collects as well-defined euhedral crystals which grow into a volume of several cc

Study of adsorption properties of impregnated charcoal for airborne iodine and methyl iodide

International Nuclear Information System (INIS)

Qi-dong, L.; Sui-yuang, H.

1985-01-01

The adsorption characteristics of airborne radioiodine and methyl iodide on impregnated charcoal were investigated. The activated charcoal tested was made from home-made oil-palm shells, and KI and TEDA were used as impregnants. A new technique was used to plot the dynamic partial adsorption isotherm at challenge concentrations (concentration range of iodine: 1-20 ppm v/v). Some adsorption properties of the impregnated charcoal were estimated with the dynamic partial adsorption isotherm. The dependences of the adsorption capacity and penetration behavior for airborne iodine and methyl iodide on the ambient conditions (temperature, relative humidity, and superficial velocity) were studied

Recovery of Americium-241 from lightning rod by the method of chemical treatment

International Nuclear Information System (INIS)

Cruz, W.H.

2013-01-01

About 95% of the lightning rods installed in the Peruvian territory have set in their structures, pose small amounts of radioactive sources such as Americium-241 ( 241 Am), fewer and Radium 226 ( 226 Ra) these are alpha emitters and have a half life of 432 years and 1600 years respectively. In this paper describes the recovery of radioactive sources of 241 Am radioactive lightning rods using the conventional chemical treatment method using agents and acids to break down the slides. The 241 Am recovered was as excitation source and alpha particle generator for analysing samples by X Ray Fluorescence, for fixing the stainless steel 241 Am technique was used electrodeposition. (author)

Temperature and concentration dependences of the electrical resistivity for alloys of plutonium with americium under normal conditions

Science.gov (United States)

Tsiovkin, Yu. Yu.; Povzner, A. A.; Tsiovkina, L. Yu.; Dremov, V. V.; Kabirova, L. R.; Dyachenko, A. A.; Bystrushkin, V. B.; Ryabukhina, M. V.; Lukoyanov, A. V.; Shorikov, A. O.

2010-01-01

The temperature and concentration dependences of the electrical resistivity for alloys of americium with plutonium are analyzed in terms of the multiband conductivity model for binary disordered substitution-type alloys. For the case of high temperatures ( T > ΘD, ΘD is the Debye temperature), a system of self-consistent equations of the coherent potential approximation has been derived for the scattering of conduction electrons by impurities and phonons without any constraints on the interaction intensity. The definitions of the shift and broadening operator for a single-electron level are used to show qualitatively and quantitatively that the pattern of the temperature dependence of the electrical resistivity for alloys is determined by the balance between the coherent and incoherent contributions to the electron-phonon scattering and that the interference conduction electron scattering mechanism can be the main cause of the negative temperature coefficient of resistivity observed in some alloys involving actinides. It is shown that the great values of the observed resistivity may be attributable to interband transitions of charge carriers and renormalization of their effective mass through strong s-d band hybridization. The concentration and temperature dependences of the resistivity for alloys of plutonium and americium calculated in terms of the derived conductivity model are compared with the available experimental data.

The biokinetics and radiotoxicology of curium: A comparison with americium

Energy Technology Data Exchange (ETDEWEB)

Menetrier, F. [CEA, Fontenay-aux-Roses (France); Taylor, D.M. [School of Chemistry, Cardiff University, Cardiff CF10 3AT (United Kingdom)], E-mail: davtay@btinternet.com; Comte, A. [CEA, Fontenay-aux-Roses (France)

2008-05-15

The human and animal data on the biokinetics of {sup 242}Cm and {sup 244}Cm are reviewed and shown to be very similar to those for {sup 241}Am. Liver and skeleton are the main organs of deposition and the retention of curium in the skeleton is very prolonged in all the species examined. Retention of both curium and americium in the liver appears to be species-dependent, being relatively rapidly removed from the liver of rats, and probably humans, but being tenaciously retained in dogs and some other species. The radiotoxicity of curium is also reviewed and it is shown that, as with {sup 241}Am, lung and bone tumour induction are the major hazards from inhaled and systemically deposited {sup 244}Cm. The use of chelating agents for the treatment of accidental contamination of the human body with {sup 242,244}Cm is also discussed.

Transfer across the human gut of environmental plutonium, americium, cobalt, caesium and technetium: studies with cockles (Cerastoderma edule) from the Irish Sea

International Nuclear Information System (INIS)

Hunt, G.J.

1998-01-01

Our previous studies have indicated lower values of the gut transfer factor ('f L values') for plutonium and americium in winkles (Littorina littorea) than adopted by ICRP. The present study was undertaken primarily to investigate whether this observation extends to other species. Samples of cockles (Cerastoderma edule) from Ravenglass, Cumbria were eaten by volunteers who provided 24 samples of urine and faeces. Urine samples indicated f L values for cockles which were higher than for winkles; for plutonium these ranged overall up to 7x10 -4 with an arithmetic mean in the range (2-3)x10 -4 , and for americium up to 2.6x10 -4 with an arithmetic mean of 1.2x10 -4 . Limited data based on volunteers eating cockles from the Solway suggest that f L values for americium may be greater at distance from Sellafield. The measured values compare with 5x10 -4 used by the ICRP for environmental forms of both elements, which would appear to provide adequate protection when calculating doses from Cumbrian cockles. Data for other nuclides were obtained by analysing faecal samples from the volunteers who ate the Ravenglass cockles. Cobalt-60 showed an f L value in the region of 0.2, twice the value currently used by ICRP. For 137 Cs, variabilities were indicated in the range 0.08 to 0.43, within the ICRP value of f L =1.0. Technetium-99 gave f L values up to about 0.6, in reasonable conformity with the ICRP value of 0.5. (author)

Analysis of perchlorate, thiocyanate, nitrate and iodide in human amniotic fluid using ion chromatography and electrospray tandem mass spectrometry

International Nuclear Information System (INIS)

Blount, Benjamin C.; Valentin-Blasini, Liza

2006-01-01

Because of health concerns surrounding in utero exposure to perchlorate, we developed a sensitive and selective method for quantifying iodide, as well as perchlorate and other sodium-iodide symporter (NIS) inhibitors in human amniotic fluid using ion chromatography coupled with electrospray ionization tandem mass spectrometry. Iodide and NIS inhibitors were quantified using a stable isotope-labeled internal standards (Cl 18 O 4 - , S 13 CN - and 15 NO 3 - with excellent assay accuracy of 100%, 98%, 99%, 95% for perchlorate, thiocyanate, nitrate and iodide, respectively, in triplicate analysis of spiked amniotic fluid sample). Excellent analytical precision (<5.2% RSD for all analytes) was found when amniotic fluid quality control pools were repetitively analyzed for iodide and NIS-inhibitors. Selective chromatography and tandem mass spectrometry reduced the need for sample cleanup, resulting in a rugged and rapid method capable of routinely analyzing 75 samples/day. Analytical response was linear across the physiologically relevant concentration range for the analytes. Analysis of a set of 48 amniotic fluid samples identified the range and median levels for perchlorate (0.057-0.71, 0.18 μg/L), thiocyanate (<10-5860, 89 μg/L), nitrate (650-8900, 1620 μg/L) and iodide (1.7-170, 8.1 μg/L). This selective, sensitive, and rapid method will help assess exposure of the developing fetus to low levels of NIS-inhibitors and their potential to inhibit thyroid function

Interruption with the Migration of Iodide by GR(CT)

International Nuclear Information System (INIS)

Min, J. H.; Lee, J. K.; Jeong, J. T.

2012-01-01

The purpose of this study is to understand the influence of green rust on the migration of iodide. GR(CT) would be major corrosion product of iron near the seawater or saline layer in underground. The GR(CT) may play an important role in the retardation of the iodide migration in a deep geological environment due to it's anionic exchange reaction. In underground radioactive waste repository, the corrosion of iron canisters would be proceed as follows; Fe(II) and/or Fe(III) dissolved from iron containers → Fe(II)(OH) 2 and/or Fe(III)(OH) 3 → Green rust → Lepidocrocite or Magnetite → Goetite etc. Generally, the green rust has known to exist in environments close to the Fe(Π)/Fe(ΠΙ) transition zone or between the oxidized layer and reduced layer in the underground. As anion exchanger and strong reducer, the green rusts can affect the migration of anions, reactions involving green rusts were poorly studied in relation to the safety assessment of radioactive waste repository

The distribution of radioiodine administrated to pregnant mice and the effect of non radioactive iodide

International Nuclear Information System (INIS)

Okui, Toyo; Kobayashi, Satoshi

1987-01-01

Radioiodine, 131 I, which has a high fission yield in the nuclear reactor, is easily taken into the human body, accumilating in the thyroid gland, when released to the environment. 131 I was administrated orally to pregnant mice, and its transportation to the tissues, particularly the fetus, was examined closely. And further, the non-radioactive iodide, i.e., KI, was administrated to see its radiation protection effect. The transportation of 131 I to the fetus is the second highest, following the thyroid gland in the mother mouse. This transportation to the fetus becomes the higher, the larger the gestation period at which the 131 I administration is made. The administration of the non-radioactive iodide has large radiation protection effect in the thyroid gland of the mother mouse and of the fetus. But, depending on its concentration, the non-radioactive iodide may conversely increase overall exposure of the fetus. (Mori, K.)

Complex formation of trivalent americium with salicylic acid at very low concentrations

International Nuclear Information System (INIS)

Melanie Mueller; Margret Acker; Steffen Taut; Gert Bernhard; Forschungszentrum Dresden-Rossendorf, Dresden

2010-01-01

For the first time, the complexation of americium(III) with salicylic acid was studied at trace metal concentrations using a 2.0 m Long Path Flow Cell for UV-vis spectroscopy. The detection limit of Am(III) in aqueous solution at pH 3.0 was found to be 5 x 10 -9 M. Two Am(III)-salicylate complexes were formed at pH 5.0 in 0.1 M NaClO 4 , indicated by a clear red shift of the absorption maximum. The absorption spectra obtained from spectrophotometric titration were analyzed by means of factor analysis and complex stabilities were calculated to be log β 110 = 2.56 ± 0.08 and log β 120 = 3.93 ± 0.19. (author)

Functionalized metal organic frameworks for effective capture of radioactive organic iodides

KAUST Repository

Li, Baiyan; Dong, Xinglong; Wang, Hao; Ma, Dingxuan; Tan, Kui; Shi, Zhan; Chabal, Yves J.; Han, Yu; Li, Jing

2017-01-01

Highly efficient capture of radioactive organic iodides (ROIs) from off-gas mixtures remains a substantial challenge for nuclear waste treatment. Current materials utilized for ROI sequestration suffer from low capacity, high cost (e.g. use of noble

Optical power limiting and transmitting properties of cadmium iodide single crystals: Temperature dependence

Energy Technology Data Exchange (ETDEWEB)

Miah, M. Idrish, E-mail: m.miah@griffith.edu.a [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)] [Biomolecular and Physical Sciences, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)] [Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)

2009-09-14

Optical limiting properties of the single crystals of cadmium iodide are investigated using ns laser pulses. It is found that the transmissions in the crystals increase with increasing temperature. However, they limit the transmissions at high input powers. The limiting power is found to be higher at higher temperature. From the measured transmission data, the photon absorption coefficients are estimated. The temperature dependence of the coefficients shows a decrease in magnitude with increasing temperature. This might be due to the temperature-dependent bandgap shift of the material. The results demonstrate that the cadmium iodide single crystals are promising materials for applications in optical power limiting devices.

Optical power limiting and transmitting properties of cadmium iodide single crystals: Temperature dependence

International Nuclear Information System (INIS)

Miah, M. Idrish

2009-01-01

Optical limiting properties of the single crystals of cadmium iodide are investigated using ns laser pulses. It is found that the transmissions in the crystals increase with increasing temperature. However, they limit the transmissions at high input powers. The limiting power is found to be higher at higher temperature. From the measured transmission data, the photon absorption coefficients are estimated. The temperature dependence of the coefficients shows a decrease in magnitude with increasing temperature. This might be due to the temperature-dependent bandgap shift of the material. The results demonstrate that the cadmium iodide single crystals are promising materials for applications in optical power limiting devices.

Methyl iodide retention on charcoal sorbents at parts-per-million concentrations

International Nuclear Information System (INIS)

Wood, G.O.; Vogt, G.J.; Kasunic, C.A.

1978-01-01

Breakthrough curves for charcoal beds challenged by air containing parts-per-million methyl iodide ( 127 I) vapor concentrations were obtained and analyzed. A goal of this research is to determine if sorbent tests at relatively high vapor concentrations give data that can be extrapolated many orders of magnitude to the region of interest for radioiodine retention and removal. Another objective is to identify and characterize parameters that are critical to the performance of a charcoal bed in a respirator cartridge application. Towards these ends, a sorbent test system was built that allows experimental variations of the parameters of challenge vapor concentration, volumetric flow rate, bed depth, bed diameter, and relative humidity. Methyl iodide breakthrough was measured at a limit of 0.002 ppM using a gas chromatograph equipped with a linearized electron capture detector. Several models that have been proposed to describe breakthrough curves were tested against experimental data. A variety of charcoals used or proposed for use in radioiodine air filtration systems have been tested against 25.7 ppM methyl iodide to obtain these parameters and protection (decomtamination) factors. Effects of challenge concentration, relative humidity, and bed diameter were also investigated. Significant challenge concentration dependence was measured (more efficiency at lower concentration) for two types of charcoals. Increased relative humidity greatly decreased breakthrough times for a given protection factor. Increased bed diameter greatly increased breakthrough times for a given protection factor. Implications of these effects for a test method are discussed

Method for ion exchange purification of sodium iodide solution from heavy metals and potassium microimpurities

International Nuclear Information System (INIS)

Smirnov, G.I.; Kachur, N.Ya.; Kostromina, O.N.; Ogorodnikova, A.A.; Khajnakov, S.A.

1990-01-01

A method of deep ion exchange purification of sodium iodide solution from heavy metals (iron, nickel, copper, lead) and potassium microimpurities is developed. The method includes multiple sorption of microimpurities on titanium phosphate with their subsequent desorption by sorbent processing with a solution with a solution of 3-6 N nitric acid, first, and then with a neutral solution of 2 % sodium thiosulfate. The given method permits to increase the purification degree of sodium iodide solution by 25-30 %. 2 tabs

Silver-Assisted Synthesis of Gold Nanorods: the Relation between Silver Additive and Iodide Impurities.

Science.gov (United States)

Jessl, Sarah; Tebbe, Moritz; Guerrini, Luca; Fery, Andreas; Alvarez-Puebla, Ramon A; Pazos-Perez, Nicolas

2018-04-17

Seed-mediated methods employing cetyltrimethylammonium bromide (CTAB) as a surfactant, and silver salts as additives, are the most common synthetic strategies for high-yield productions of quality Au nanorods. However, the mechanism of these reactions is not yet fully understood and, importantly, significant lab-to-lab reproducibility issues still affect these protocols. In this study, the direct correlation between the hidden content of iodide impurities in CTAB reagents, which can drastically differ from different suppliers or batches, and the optimal concentration of silver required to maximize the nanorods yield is demonstrated. As a result, high-quality nanorods are obtained at different iodide contents. These results are interpreted based on the different concentrations of CTAB and cetyltrimethylammonium iodide (CTAI) complexes with Ag + and Au + metal ions in the growth solution, and their different binding affinity and reduction potential on distinct crystallographic planes. Notably, the exhaustive conversion of CTAI-Au + to CTAI-Ag + appears to be the key condition for maximizing the nanorod yield. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Silver iodide reduction in aqueous solution: application to iodine enhanced separation during spent nuclear fuels reprocessing

International Nuclear Information System (INIS)

Badie, Jerome

2002-01-01

Silver iodide is a key-compound in nuclear chemistry either in accidental conditions or during the reprocessing of spent nuclear fuel. In that case, the major part of iodine is released in molecular form into the gaseous phase at the time of dissolution in nitric acid. In French reprocessing plants, iodine is trapped in the dissolver off-gas treatment unit by two successive steps: the first consists in absorption by scrubbing with a caustic soda solution and in the second, residual iodine is removed from the gaseous stream before the stack by chemisorption on mineral porous traps made up of beds of amorphous silica or alumina porous balls impregnated with silver nitrate. Reactions of iodine species with the impregnant are assumed to lead to silver iodide and silver iodate. Enhanced separation policy would make necessary to recover iodine from the filters by silver iodide dissolution during a reducing treatment. After a brief silver-iodine chemical bibliographic review, the possible reagents listed in the literature were studied. The choice has been made to use ascorbic acid and hydroxylamine. An experimental work on silver iodide reduction by this two compounds allowed us to determinate reaction products, stoichiometry and kinetics parameters. Finally, the process has been initiated on stable iodine loaded filters samples. (author) [fr

Towards a biochemical and structural characterisation of the sodium-iodide sym-porter (Nis)

International Nuclear Information System (INIS)

Darrouzet, E.; Marcellin, D.; Huc, S.; Quemeneur, E.; Pourcher, T.

2006-01-01

Iodide is essential for thyroid hormone biosynthesis in mammals, and therefore for the control of cell metabolism and the development of the central nervous system in the foetus and newborns, but is relatively scarce element in the environment. To ensure its accumulation, the thyroid gland has evolved a remarkably efficient system, the sodium-iodide sym-porter (NIS), that was first characterized at the molecular level 10 years ago (1). NIS is an intrinsic protein mainly located in the basolateral membrane of thyroid follicular cells where it actively transports iodide ions using the sodium gradient as a driving force (2,3). In addition, this transporter has been found in lactating mammary gland, stomach, and salivary glands, and its mRNA was detected in brain, ovaries, testis. To date, the physiological role of NIS in these organs is not yet identified (3,4).The capacity of NIS to mediate the accumulation of radioactive iodide has been exploited for many years in the diagnosis of thyroid cancer as well as for the detection and radiotherapy of derived metastases. Moreover, the presence of NIS in some breast tumours and the possibility to express it by targeted gene therapy in tumour cells where it is not naturally present could also widen its medical application (4-7). In case of accidental contamination, NIS would also be responsible for accumulation of radioisotopes in the thyroid and for their transfer to the milk and the newborn, eventually causing thyroid cancers. This has motivated our research program in the perspective of designing novel specific therapeutics. During the last decade, the gene encoding the thyroid NIS has been identified and sequenced in various species including rat, mouse and human (1, 8). It was also demonstrated that the protein expression and activity are highly regulated both at the transcriptional and post-translational levels (3). A preliminary topological mode could be drawn from the protein sequence. It proposes a general

1-(3-Iodopropyl-4-methylquinolin-1-ium Iodide

Directory of Open Access Journals (Sweden)

Todor Deligeorgiev

2015-11-01

Full Text Available A solvent-free “one-pot” synthetic approach to 1-(3-iodopropyl-4-methylquinolin-1-ium iodide is reported in the present work. The title compound is derived from N-alkylation of 4-methylquinoline with 1,3-diiodopropane proceeded at room temperature. The target quinolinium salt is obtained in a highly pure form. It’s structure was evaluated by 1H-NMR, 13C-NMR, and DEPT135 spectra.

Expedient Method for Samarium(II) Iodide Preparation Utilizing a Flow Approach

Czech Academy of Sciences Publication Activity Database

Voltrová, Svatava; Šrogl, Jiří

2013-01-01

Roč. 24, č. 3 (2013), s. 394-396 ISSN 0936-5214 R&D Projects: GA MŠk LH12013 Institutional support: RVO:61388963 Keywords : flow * samarium * iodide * reduction Subject RIV: CC - Organic Chemistry Impact factor: 2.463, year: 2013

Osteosarcoma induction by plutonium-239, americium-241 and neptunium-237 : the problem of deriving risk estimates for man

International Nuclear Information System (INIS)

Taylor, D.M.

1988-01-01

Spontaneous bone cancer (osteosarcoma) represents only about 0.3% of all human cancers, but is well known to be inducible in humans by internal contamination with radium-226 and radium-224. plutonium-239, americium-241 and neptunium-237 form, or will form, the principal long-lived alpha particle emitting components of high activity waste and burnt-up nuclear fuel elements. These three nuclides deposit extensively in human bone and although, fortunately, no case of a human osteosarcoma induced by any of these nuclides is known, evidence from animal studies suggests that all three are more effective than radium-226 in inducing osteosarcoma. The assumption that the ratio of the risk factors, the number of osteosarcoma expected per 10000 person/animal Gy, for radium-226 and any other bone-seeking alpha-emitter will be independent of animal species has formed the basis of all the important studies of the radiotoxicity of actinide nuclides in experimental animals. The aim of this communication is to review the risk factors which may be calculated from the various animal studies carried out over the last thirty years with plutonium-237, americium-241 and neptunium-237 and to consider the problems which may arise in extrapolating these risk factors to homo sapiens

Evaluation of perturbations in serum thyroid hormones during human pregnancy due to dietary iodide and perchlorate exposure using a biologically based dose-response model.

Science.gov (United States)

Lumen, Annie; Mattie, David R; Fisher, Jeffrey W

2013-06-01

A biologically based dose-response model (BBDR) for the hypothalamic pituitary thyroid (HPT) axis was developed in the near-term pregnant mother and fetus. This model was calibrated to predict serum levels of iodide, total thyroxine (T4), free thyroxine (fT4), and total triiodothyronine (T3) in the mother and fetus for a range of dietary iodide intake. The model was extended to describe perchlorate, an environmental and food contaminant, that competes with the sodium iodide symporter protein for thyroidal uptake of iodide. Using this mode-of-action framework, simulations were performed to determine the daily ingestion rates of perchlorate that would be associated with hypothyroxinemia or onset of hypothyroidism for varying iodide intake. Model simulations suggested that a maternal iodide intake of 75 to 250 µg/day and an environmentally relevant exposure of perchlorate (~0.1 µg/kg/day) did not result in hypothyroxinemia or hypothyroidism. For a daily iodide-sufficient intake of 200 µg/day, the dose of perchlorate required to reduce maternal fT4 levels to a hypothyroxinemic state was estimated at 32.2 µg/kg/day. As iodide intake was lowered to 75 µg/day, the model simulated daily perchlorate dose required to cause hypothyroxinemia was reduced by eightfold. Similarly, the perchlorate intake rates associated with the onset of subclinical hypothyroidism ranged from 54.8 to 21.5 µg/kg/day for daily iodide intake of 250-75 µg/day. This BBDR-HPT axis model for pregnancy provides an example of a novel public health assessment tool that may be expanded to address other endocrine-active chemicals found in food and the environment.

Role of endoplasmic reticulum stress-induced apoptosis in rat thyroid toxicity caused by excess fluoride and/or iodide.

Science.gov (United States)

Liu, Hongliang; Hou, Changchun; Zeng, Qiang; Zhao, Liang; Cui, Yushan; Yu, Linyu; Wang, Lingzhi; Zhao, Yang; Nie, Junyan; Zhang, Bin; Wang, Aiguo

2016-09-01

Excess fluoride and iodide coexist in drinking water in many regions, but few studies have investigated the single or interactive effects on thyroid in vivo. In our study, Wistar rats were exposed to excess fluoride and/or iodide through drinking water for 2 or 8 months. The structure and function of the thyroid, cells apoptosis and the expression of inositol-requiring enzyme 1 (IRE1) pathway-related factors were analyzed. Results demonstrated that excess fluoride and/or iodide could change thyroid follicular morphology and alter thyroid hormone levels in rats. After 8 months treatment, both single and co-exposure of the two microelements could raise the thyroid cells apoptosis. However, the expressions of IRE1-related factors were only increased in fluoride-alone and the combined groups. In conclusion, thyroid structure and thyroid function were both affected by excess fluoride and/or iodide. IRE1-induced apoptosis were involved in this cytotoxic process caused by fluoride or the combination of two microelements. Copyright © 2016 Elsevier B.V. All rights reserved.

Actinide Oxidation State and O/M Ratio in Hypostoichiometric Uranium-Plutonium-Americium U0.750Pu0.246Am0.004O2-x Mixed Oxides.

Science.gov (United States)

Vauchy, Romain; Belin, Renaud C; Robisson, Anne-Charlotte; Lebreton, Florent; Aufore, Laurence; Scheinost, Andreas C; Martin, Philippe M

2016-03-07

Innovative americium-bearing uranium-plutonium mixed oxides U1-yPuyO2-x are envisioned as nuclear fuel for sodium-cooled fast neutron reactors (SFRs). The oxygen-to-metal (O/M) ratio, directly related to the oxidation state of cations, affects many of the fuel properties. Thus, a thorough knowledge of its variation with the sintering conditions is essential. The aim of this work is to follow the oxidation state of uranium, plutonium, and americium, and so the O/M ratio, in U0.750Pu0.246Am0.004O2-x samples sintered for 4 h at 2023 K in various Ar + 5% H2 + z vpm H2O (z = ∼ 15, ∼ 90, and ∼ 200) gas mixtures. The O/M ratios were determined by gravimetry, XAS, and XRD and evidenced a partial oxidation of the samples at room temperature. Finally, by comparing XANES and EXAFS results to that of a previous study, we demonstrate that the presence of uranium does not influence the interactions between americium and plutonium and that the differences in the O/M ratio between the investigated conditions is controlled by the reduction of plutonium. We also discuss the role of the homogeneity of cation distribution, as determined by EPMA, on the mechanisms involved in the reduction process.

New colorimetric and fluorometric sensing strategy based on the anisotropic growth of histidine-mediated synthesis of gold nanoclusters for iodide-specific detection.

Science.gov (United States)

Wang, Yifeng; Zhu, Haiyan; Yang, Xiaoming; Dou, Yao; Liu, Zhongde

2013-04-07

Iodide, as a biologically important anion, it remains a worthwhile yet challenging undertaking to find a sensitive and specific approach to provide a technically simple iodide detection. In this article, it was found that no other ions than iodide-induced anisotropic growth of gold nanocrystals (AuNCs) originated from a small molecule, histidine-mediated synthesis of AuNCs, were observed. Simultaneously, it is accompanied by the fluorescence quenching of AuNCs and the naked-eye visible color change. Therefore, a new colorimetric and fluorometric sensing strategy was developed for the iodide-specific detection. Compared with currently reported methods, the present one displays the advantages of the visual detection and simplicity. The quenched fluorescence and enhanced surface plasmon resonance absorbance were found to be proportional to the iodide concentration over the range of 0.8-60 and 1.2-50 μM with a detection limit (3σ) of 118 nM and 215 nM, respectively.

Synthesis of zirconia sol stabilized by trivalent cations (yttrium and neodymium or americium): a precursor for Am-bearing cubic stabilized zirconia.

Science.gov (United States)

Lemonnier, Stephane; Grandjean, Stephane; Robisson, Anne-Charlotte; Jolivet, Jean-Pierre

2010-03-07

Recent concepts for nuclear fuel and targets for transmuting long-lived radionuclides (minor actinides) and for the development of innovative Gen-IV nuclear fuel cycles imply fabricating host phases for actinide or mixed actinide compounds. Cubic stabilized zirconia (Zr, Y, Am)O(2-x) is one of the mixed phases tested in transmutation experiments. Wet chemical routes as an alternative to the powder metallurgy are being investigated to obtain the required phases while minimizing the handling of contaminating radioactive powder. Hydrolysis of zirconium, neodymium (a typical surrogate for americium) and yttrium in aqueous media in the presence of acetylacetone was firstly investigated. Progressive hydrolysis of zirconium acetylacetonate and sorption of trivalent cations and acacH on the zirconia particles led to a stable dispersion of nanoparticles (5-7 nm) in the 6-7 pH range. This sol gels with time or with temperature. The application to americium-containing solutions was then successfully tested: a stable sol was synthesized, characterized and used to prepare cubic stabilized zirconia (Zr, Y, Am)O(2-x).

Electrokinetic properties and conductance relaxation of polystyrene and silver iodide plugs

NARCIS (Netherlands)

Hoven, van den J.J.

1984-01-01

This thesis describes an experimental study on the electrokinetic and electrical properties of concentrated polystyrene and silver iodide dispersions. The purpose of the study is to obtain information on the structure of the electrical double layer at the solid-liquid interface. Special

Feasibility Study for the Reduction of Perchlorate, Iodide, and Other Aqueous Anions

National Research Council Canada - National Science Library

Clewell, Rebecca A; Tsui, David T; Mattie, David R

1999-01-01

Cyclic Voltammetry (CV) was used as a technique to determine the feasibility of the use of a coulometric detector in the determination of perchlorate, iodide, and various other anions commonly found in drinking water...

Iodide Residues in Milk Vary between Iodine-Based Teat Disinfectants

NARCIS (Netherlands)

French, Elizabeth A; Mukai, Motoko; Zurakowski, Michael; Rauch, Bradley; Gioia, Gloria; Hillebrandt, Joseph R; Henderson, Mark; Schukken, Ynte H; Hemling, Thomas C

Majority of iodine found in dairy milk comes from the diet and teat disinfection products used during milking process. The objective of this study was to evaluate the effects of 4 iodine-based teat dips on milk iodide concentrations varying in iodine level (0.25% vs. 0.5%, w/w), normal low viscosity

Recovery of plutonium and americium from chloride salt wastes by solvent extraction

International Nuclear Information System (INIS)

Reichley-Yinger, L.; Vandegrift, G.F.

1987-01-01

Plutonium and americium can be recovered from aqueous waste solutions containing a mixture of HCl and chloride salt wastes by the coupling of two solvent extraction systems: tributyl phosphate (TBP) in tetrachloroethylene (TCE) and octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in TCE. In the flowsheet developed, the salt wastes are dissolved in HCl, the Pu(III) is oxidized to the IV state with NaClO 2 and recovered in the TBP-TCE cycle, and the Am is then removed from the resultant raffinate by the CMPO-TCE cycle. The consequences of the feed solution composition and extraction behavior of these species on the process flowsheet design, the Pu-product purity, and the decontamination of the aqueous raffinate from transuranic elements are discussed. 16 refs., 6 figs

Magnesium ionophore II as an extraction agent for trivalent europium and americium

Energy Technology Data Exchange (ETDEWEB)

Makrlik, Emanuel [Czech Univ. of Life Sciences, Prague (Czech Republic). Faculty of Environmental Sciences; Vanura, Petr [Univ. of Chemistry and Technology, Prague (Czech Republic). Dept. of Analytical Chemistry

2016-11-01

Solvent extraction of microamounts of trivalent europium and americium into nitrobenzene by using a mixture of hydrogen dicarbollylcobaltate (H{sup +}B{sup -}) and magnesium ionophore II (L) was studied. The equilibrium data were explained assuming that the species HL{sup +}, HL{sup +}{sub 2}, ML{sup 3+}{sub 2}, and ML{sup 3+}{sub 3} (M{sup 3+} = Eu{sup 3+}, Am{sup 3+}; L=magnesium, ionophore II) are extracted into the nitrobenzene phase. Extraction and stability constants of the cationic complex species in nitrobenzene saturated with water were determined and discussed. From the experimental results it is evident that this effective magnesium ionophore II receptor for the Eu{sup 3+} and Am{sup 3+} cations could be considered as a potential extraction agent for nuclear waste treatment.

Comparison of acid leachate and fusion methods to determine plutonium and americium in environmental samples

International Nuclear Information System (INIS)

Smith, L.L.; Markun, F.; TenKate, T.

1992-06-01

The Analytical Chemistry Laboratory at Argonne National Laboratory performs radiochemical analyses for a wide variety of sites within the Department of Energy complex. Since the chemical history of the samples may vary drastically from site to site, the effectiveness of any analytical technique may also vary. This study compares a potassium fluoride-pyrosulfate fusion technique with an acid leachate method. Both normal and high-fired soils and vegetation samples were analyzed for both americium and plutonium. Results show both methods work well, except for plutonium in high-fired soils. Here the fusion method provides higher accuracy

Microstructure and elemental distribution of americium containing MOX fuel under the short term irradiation tests

International Nuclear Information System (INIS)

Tanaka, Kosuke; Hirosawa, Takashi; Obayashi, Hiroshi; Koyama, Shin Ichi; Yoshimochi, Hiroshi; Tanaka, Kenya

2008-01-01

In order to investigate the effect of americium addition to MOX fuels on the irradiation behavior, the 'Am-1' program is being conducted in JAEA. The Am-1 program consists of two short term irradiation tests of 10-minute and 24 hour irradiations and a steady-state irradiation test. The short-term irradiation tests were successfully completed and the post irradiation examinations (PIEs) are in progress. The PIEs for Am-containing MOX fuels focused on the microstructural evolution and redistribution behavior of Am at the initial stage of irradiation and the results to date are reported

PI3K activation is associated with intracellular sodium/iodide symporter protein expression in breast cancer

International Nuclear Information System (INIS)

Knostman, Katherine AB; McCubrey, James A; Morrison, Carl D; Zhang, Zhaoxia; Capen, Charles C; Jhiang, Sissy M

2007-01-01

The sodium/iodide symporter (NIS) is a membrane glycoprotein mediating active iodide uptake in the thyroid gland and is the molecular basis for radioiodide imaging and therapeutic ablation of thyroid carcinomas. NIS is expressed in the lactating mammary gland and in many human breast tumors, raising interest in similar use for diagnosis and treatment. However, few human breast tumors have clinically evident iodide uptake ability. We previously identified PI3K signaling as important in NIS upregulation in transgenic mouse models of breast cancer, and the PI3K pathway is commonly activated in human breast cancer. NIS expression, subcellular localization, and function were analyzed in MCF-7 human breast cancer cells and MCF-7 cells stably or transiently expressing PI3K p110alpha subunit using Western blot of whole cell lysate, cell surface biotinylation Western blot and immunofluorescence, and radioiodide uptake assay, respectively. NIS localization was determined in a human breast cancer tissue microarray using immunohistochemical staining (IHC) and was correlated with pre-existing pAkt IHC data. Statistical analysis consisted of Student's t-test (in vitro studies) or Fisher's Exact Test (in vivo correlational studies). In this study, we demonstrate that PI3K activation in MCF-7 human mammary carcinoma cells leads to expression of underglycosylated NIS lacking cell surface trafficking necessary for iodide uptake ability. PI3K activation also appears to interfere with cell surface trafficking of exogenous NIS as well as all-trans retinoic acid-induced endogenous NIS. A correlation between NIS expression and upregulation of PI3K signaling was found in a human breast cancer tissue microarray. Thus, the PI3K pathway likely plays a major role in the discordance between NIS expression and iodide uptake in breast cancer patients. Further study is warranted to realize the application of NIS-mediated radioiodide ablation in breast cancer

Non-radioactive determination of the penetration of methyl iodide through impregnated charcoals during dosing and purging

International Nuclear Information System (INIS)

Romans, J.B.; Deitz, V.R.

1979-01-01

A laboratory procedure is described using methyl iodide-127 which had the same linear flow of air (12.2 m/min) and contact time (0.25 sec.) as the RDT M16 Test Procedure. Only one-fourth of the charcoal was used (in a bed 2.54 cm diameter and 5.08 cm high) and the required dose of methyl iodide-127 was reduced from 5.25 to 1.31 mg. The inlet concentrations were determined with a gas chromatograph and the effluent concentrations with a modified microcoulombmeter. Two calibration procedures were used: (1) known vapor pressure of iodine crystals, and (2) quantitative pyrolysis of the methyl iodide-127 delivered from certified permeation tubes. Five charcoals and three impregnations were used in this study. Typical behaviors are given in 90% RH air with the charcoals either prehumidified for 16 hours at 90% RH or without the prehumidification. The breakthrough curves, concentration versus time, rose very slowly for the first 120 minutes and then more rapidly for an additional time. The lack of a dependence on the magnitude of the dose is compatible with a catalytic trapping mechanism. In the case of KI/sub x/ impregnations, there was excess emission of iodine during purging over that introduced as methyl iodide-127 which must have originated in the reservoir of iodine contained in the impregnation

Polymeric membrane sensors based on Cd(II) Schiff base complexes for selective iodide determination in environmental and medicinal samples.

Science.gov (United States)

Singh, Ashok Kumar; Mehtab, Sameena

2008-01-15

The two cadmium chelates of schiff bases, N,N'-bis(salicylidene)-1,4-diaminobutane, (Cd-S(1)) and N,N'-bis(salicylidene)-3,4-diaminotoluene (Cd-S(2)), have been synthesized and explored as ionophores for preparing PVC-based membrane sensors selective to iodide(I) ion. Potentiometric investigations indicate high affinity of these receptors for iodide ion. Polyvinyl chloride (PVC)-based membranes of Cd-S(1) and Cd-S(2) using as hexadecyltrimethylammonium bromide (HTAB) cation discriminator and o-nitrophenyloctyl ether (o-NPOE), dibutylphthalate (DBP), acetophenone (AP) and tributylphosphate (TBP) as plasticizing solvent mediators were prepared and investigated as iodide-selective sensors. The best performance was shown by the membrane of composition (w/w) of (Cd-S(1)) (7%):PVC (31%):DBP (60%):HTAB (2%). The sensor works well over a wide concentration range 5.3x10(-7) to 1.0x10(-2)M with Nernstian compliance (59.2mVdecade(-1) of activity) within pH range 2.5-9.0 with a response time of 11s and showed good selectivity for iodide ion over a number of anions. The sensor exhibits adequate life (3 months) with good reproducibility (S.D.+/-0.24mV) and could be used successfully for the determination of iodide content in environmental water samples and mouth wash samples.

Preliminary Design of Molecular Sieve for Removing Organic Iodide in Containment Filtered Venting System

Energy Technology Data Exchange (ETDEWEB)

Park, Tong Kyu; Shin, So Eun; Lee, Byung Chul [Heungdeok IT Valley Bldg., Yongin (Korea, Republic of); Kim, Hong Hyun; Lee, Kyung Jun [Gemvax and KAEL Inc., Daejeon (Korea, Republic of)

2014-05-15

In this paper, to increase the DF for gaseous iodine species, especially organic iodide, molecular sieve filled by silver exchanged zeolites is proposed and designed preliminarily. Its aerodynamic analysis is also performed and presented. In order to increase the DF for gaseous organic iodide, deep-bed type molecular sieve was proposed and designed preliminarily. Total 1,620kg of silver exchanged zeolites were filled evenly in 10 beds of the molecular sieve. The safety factor in the case of 20m{sup 3}/s will be smaller than the counterpart of the standard case (6m{sup 3}/s). However, if the adsorption capacity of the zeolites is larger than 3.09mg/g when the residence time is 0.09 second, the designed molecular sieve can be used at 20m3/s of volumetric flow rate. The removal efficiency for organic iodide should be considered as well as economical aspects in the design of molecular sieve. In the event of nuclear power plant (NPP) severe accident, the nuclear reactor containment might suffer damage resulting from overpressure caused by decay heat. In order to prevent this containment damage, containment venting has been considered as one of effective methods. However, since vented gases contain radioactive fission products, they should be filtered to be released to environment. Generally, containment filtered venting system (CFVS) is installed on NPP to achieve this aim. Even though great amount of efforts have been devoted to developing the CFVS using various filtering methods, the decontaminant factor (DF) for radioactive gaseous iodide is still unsatisfactory while DFs for radioactive aerosols and elemental iodine are very high.

Density of simulated americium/curium melter feed solution

International Nuclear Information System (INIS)

Rudisill, T.S.

1997-01-01

Vitrification will be used to stabilize an americium/curium (Am/Cm) solution presently stored in F-Canyon for eventual transport to Oak Ridge National Laboratory and use in heavy isotope production programs. Prior to vitrification, a series of in-tank oxalate precipitation and nitric/oxalic acid washes will be used to separate these elements and lanthanide fission products from the bulk of the uranium and metal impurities present in the solution. Following nitric acid dissolution and oxalate destruction, the solution will be denitrated and evaporated to a dissolved solids concentration of approximately 100 g/l (on an oxide basis). During the Am/Cm vitrification, an airlift will be used to supply the concentrated feed solution to a constant head tank which drains through a filter and an in-line orifice to the melter. Since the delivery system is sensitive to the physical properties of the feed, a simulated solution was prepared and used to measure the density as a function of temperature between 20 to 70 degrees C. The measured density decreased linearly at a rate of 0.0007 g/cm3/degree C from an average value of 1.2326 g/cm 3 at 20 degrees C to an average value of 1.1973g/cm 3 at 70 degrees C

Density of simulated americium/curium melter feed solution

Energy Technology Data Exchange (ETDEWEB)

Rudisill, T.S.

1997-09-22

Vitrification will be used to stabilize an americium/curium (Am/Cm) solution presently stored in F-Canyon for eventual transport to Oak Ridge National Laboratory and use in heavy isotope production programs. Prior to vitrification, a series of in-tank oxalate precipitation and nitric/oxalic acid washes will be used to separate these elements and lanthanide fission products from the bulk of the uranium and metal impurities present in the solution. Following nitric acid dissolution and oxalate destruction, the solution will be denitrated and evaporated to a dissolved solids concentration of approximately 100 g/l (on an oxide basis). During the Am/Cm vitrification, an airlift will be used to supply the concentrated feed solution to a constant head tank which drains through a filter and an in-line orifice to the melter. Since the delivery system is sensitive to the physical properties of the feed, a simulated solution was prepared and used to measure the density as a function of temperature between 20 to 70{degrees} C. The measured density decreased linearly at a rate of 0.0007 g/cm3/{degree} C from an average value of 1.2326 g/cm{sup 3} at 20{degrees} C to an average value of 1.1973g/cm{sup 3} at 70{degrees} C.

Selective gettering of hydrogen in high pressure metal iodide lamps

International Nuclear Information System (INIS)

Kuus, G.

1976-01-01

One of the main problems in the manufacture of high pressure gas discharge lamps is the elimination of gaseous impurities from their arc tubes. Long degassing processes of all the lamp components are necessary in order to produce lamps with a low ignition voltage and good maintenance of the radiation properties. The investigation described deals with a selective getter place in the arc tube which can replace the long degassing process. The getter consists of a piece of yttrium encapsulated in thin tantalum foil. By this way it is possible to use the gettering action of tantalum and yttrium without having reaction between the metal iodide of the arc tube and yttrium. Yttrium is used because this metal can adsorb a large quantity of hydrogen even at a temperature of 1000 0 C. Hydrogen forms the main gaseous impurity in the high pressure metal iodide lamp. For this reason the adsorption properties like adsorption rate and capacity of the tantalum--yttrium getter for hydrogen are examined, and the results obtained from lamp experiments are given

Toxic impact of bromide and iodide on drinking water disinfected with chlorine or chloramines.

Science.gov (United States)

Yang, Yang; Komaki, Yukako; Kimura, Susana Y; Hu, Hong-Ying; Wagner, Elizabeth D; Mariñas, Benito J; Plewa, Michael J

2014-10-21

Disinfectants inactivate pathogens in source water; however, they also react with organic matter and bromide/iodide to form disinfection byproducts (DBPs). Although only a few DBP classes have been systematically analyzed for toxicity, iodinated and brominated DBPs tend to be the most toxic. The objectives of this research were (1) to determine if monochloramine (NH2Cl) disinfection generated drinking water with less toxicity than water disinfected with free chlorine (HOCl) and (2) to determine the impact of added bromide and iodide in conjunction with HOCl or NH2Cl disinfection on mammalian cell cytotoxicity and genomic DNA damage induction. Water disinfected with chlorine was less cytotoxic but more genotoxic than water disinfected with chloramine. For both disinfectants, the addition of Br(-) and I(-) increased cytotoxicity and genotoxicity with a greater response observed with NH2Cl disinfection. Both cytotoxicity and genotoxicity were highly correlated with TOBr and TOI. However, toxicity was weakly and inversely correlated with TOCl. Thus, the forcing agents for cytotoxicity and genotoxicity were the generation of brominated and iodinated DBPs rather than the formation of chlorinated DBPs. Disinfection practices need careful consideration especially when using source waters containing elevated bromide and iodide.

Iodide Sorption to Clays and the Relationship to Surface Charge and Clay Texture - 12356

Energy Technology Data Exchange (ETDEWEB)

Miller, Andrew; Kruichiak, Jessica; Tellez, Hernesto; Wang, Yifeng [Sandia National Laboratories, Albuquerque, NM 87185 (United States)

2012-07-01

Iodine is assumed to behave conservatively in clay barriers around nuclear waste repositories and in natural sediments. Batch experiments tend to show little to no sorption, while in column experiments iodine is often retarded relative to tritiated water. Current surface complexation theory cannot account for negatively charged ion sorption to a negatively charged clay particle. Surface protonation and iodide sorption to clay minerals were examined using surface titrations and batch sorption experiments with a suite of clay minerals. Surface titrations were completed spanning a range of both pH values and ionic strengths. For reference, similar titrations were performed on pure forms of an Al-O powder. The titration curves were deconvoluted to attain the pKa distribution for each material at each ionic strength. The pKa distribution for the Al-O shows two distinct peaks at 4.8 and 7.5, which are invariant with ionic strength. The pKa distribution of clays was highly variable between the different minerals and as a function of ionic strength. Iodide sorption experiments were completed at high solid:solution ratios to exacerbate sorption properties. Palygorskite and kaolinite had the highest amount of iodide sorption and montmorillonite had the least. (authors)

Organic iodide capture using a zeolite dry filtration

International Nuclear Information System (INIS)

Park, Sanggil; Sung, Joonyoung; Kim, Gi-ppeum; Lee, Jaeyoung

2017-01-01

An organic iodide, especially, methyl iodide (CH 3 I) would generated non-negligibly from a severe accident in a nuclear power plant. This CH 3 I will be dangerous for human when it was inhaled, it is highly toxic and causes a serious nerve disorder. Even it is a major contributor to a thyroid cancer. In order to prevent its environmental release, it is required to decontaminate using a filtration system. For the removal of CH 3 I from the release gases, wet-type is not ideal due to a high re-volatile characteristics of CH 3 I. It may become volatile after dissolving in a pool and forms CH 3 I again at the surface of water pool. Therefore, a dry-filtration should be installed to remove the CH 3 I. In this study, we preliminary investigate the characteristics of zeolite filtration methods for the removal of CH 3 I. We used both silver ion exchanged ZSM-5-zeolite (Ag+-ZSM-5) to study the effect of silver ion for the removal of iodine from CH 3 I. In summary, the CH 3 I capture tests using a silver ion exchanged zeolite was conducted in the coupled TGAGC test set-up. The mass change of the sample and concentration of CH 3 I were measured. The samples were investigated by the SEM/EDS to see its surface characteristics.

Studying the iodine leaching from the compositions based on epoxide resin and lead iodide

International Nuclear Information System (INIS)

Kalinin, N.N.; Elizarova, A.N.

1988-01-01

When studying iodine leaching, the possibility to use solid compositions, produced by incorporation of dry powdered lead iodide and its aqueous suspension into epoxide resin for long-term immobilization of iodine-129 under conditions of monitored storage, is evaluated. Analysis of the results obtained has shown that leaching rate in the first 4 days has the maximum value and constitutes (4.2 - 2700.0) x 10 -6 cm/day. Then the process of leaching is determined by diffusion mechanism. For samples, prepared by wet lead iodide incorporation the rate of leaching is higher than that of the corresponding samples prepared by dry compound incorporation

Liquid-liquid extraction of plutonium and americium by cekanoic acid from alkaline medium

International Nuclear Information System (INIS)

Venugopal Chetty, K.; Sagar, V.; Swarup, R.

2001-01-01

Liquid-liquid extraction studies of plutonium and americium from aqueous carbonate medium using a high molecular weight carboxylic acid namely cekanoic acid in different diluents has been carried out. The distribution ratio (D) values for Pu(IV) and Am(III) under various parameters such as concentration of extractant, Na 2 CO 3 and initial pH were obtained. Results indicated that Pu(IV) and Am(III) could be satisfactorily extracted together or individually from aqueous carbonate medium using cekanoic acid in different diluents like carbon tetrachloride, cyclohexane, toluene, n-dodecane or solvesso-100. The D values for Pu(IV) and Am(III) also indicated the possibility of their mutual separation. The back extraction of Pu and Am with different reagents was also studied. (orig.)

Enthalpies of potassium iodide dissolution in dimethyl acetamide mixtures with water

International Nuclear Information System (INIS)

Privalova, N.M.; Gritsenko, S.I.; Vorob'ev, A.F.

1986-01-01

Enthalpies of potassium iodide dissolution in mixed dimethyl acetamide - water solvent at 298.15 K in the whole range of dimethyl acetamide compositions are measured by the calorimetric method. From the plots of KI dissolution enthalpy dependence and dependence of experimental ΔH p∞ 0 value deviations from calculational ones on solvent composition, as well as from the results of calculation of solvate shell composition of potassium iodide ions in the mixed solvent, it is obvious that in the region of 0-15 mol% concentrations of dimethyl acetamide insufficient enrichment of solvate ion shells by dimethyl acetamide (DMAA) occurs, in the region of 15-40 mol% DMAA compositions enrichment of solvate shells of ions by water occurs, in the region of 40-100 mol% DMAA enrichment of solvate ion shells by the organic component in comparison with mixture compostion occurs. Maximum enrichment of solvate ion shells by mixture components in three above mentioned regions of the mixed solvent occurs at 10, 30 and 80 mol% DMAA concentrations

Studying Equilibrium in the Chemical Reaction between Ferric and Iodide Ions in Solution Using a Simple and Inexpensive Approach

Science.gov (United States)

Nikolaychuk, Pavel Anatolyevich; Kuvaeva, Alyona Olegovna

2016-01-01

A laboratory experiment on the study of the chemical equilibrium based on the reaction between ferric and iodide ions in solution with the formation of ferrous ions, free iodine, and triiodide ions is developed. The total concentration of iodide and triiodide ions in the reaction mixture during the reaction is determined by the argentometric…

Rapid, specific determination of iodine and iodide by combined solid-phase extraction/diffuse reflectance spectroscopy

Science.gov (United States)

Arena, Matteo P.; Porter, Marc D.; Fritz, James S.

2002-01-01

A new, rapid methodology for trace analysis using solid-phase extraction is described. The two-step methodology is based on the concentration of an analyte onto a membrane disk and on the determination by diffuse reflectance spectroscopy of the amount of analyte extracted on the disk surface. This method, which is adaptable to a wide range of analytes, has been used for monitoring ppm levels of iodine and iodide in spacecraft water. Iodine is used as a biocide in spacecraft water. For these determinations, a water sample is passed through a membrane disk by means of a 10-mL syringe that is attached to a disk holder assembly. The disk, which is a polystyrene-divinylbenzene composite, is impregnated with poly(vinylpyrrolidone) (PVP), which exhaustively concentrates iodine as a yellow iodine-PVP complex. The amount of concentrated iodine is then determined in only 2 s by using a hand-held diffuse reflectance spectrometer by comparing the result with a calibration curve based on the Kubelka-Munk function. The same general procedure can be used to determine iodide levels after its facile and exhaustive oxidation to iodine by peroxymonosulfate (i.e., Oxone reagent). For samples containing both analytes, a two-step procedure can be used in which the iodide concentration is calculated from the difference in iodine levels before and after treatment of the sample with peroxymonosulfate. With this methodology, iodine and iodide levels in the 0.1-5.0 ppm range can be determined with a total workup time of approximately 60 s with a RSD of approximately 6%.

High Photon-to-Current Conversion in Solar Cells Based on Light-Absorbing Silver Bismuth Iodide.

Science.gov (United States)

Zhu, Huimin; Pan, Mingao; Johansson, Malin B; Johansson, Erik M J

2017-06-22

Here, a lead-free silver bismuth iodide (AgI/BiI 3 ) with a crystal structure with space group R3‾ m is investigated for use in solar cells. Devices based on the silver bismuth iodide deposited from solution on top of TiO 2 and the conducting polymer poly(3-hexylthiophene-2,5-diyl) (P3HT) as a hole-transport layer are prepared and the photovoltaic performance is very promising with a power conversion efficiency over 2 %, which is higher than the performance of previously reported bismuth-halide materials for solar cells. Photocurrent generation is observed between 350 and 700 nm, and the maximum external quantum efficiency is around 45 %. The results are compared to solar cells based on the previously reported material AgBi 2 I 7 , and we observe a clearly higher performance for the devices with the new silver and bismuth iodides composition and different crystal structure. The X-ray diffraction spectrum of the most efficient silver bismuth iodide material shows a hexagonal crystal structure with space group R3‾ m, and from the light absorption spectrum we obtain an indirect band gap energy of 1.62 eV and a direct band gap energy of 1.85 eV. This report shows the possibility for finding new structures of metal-halides efficient in solar cells and points out new directions for further exploration of lead-free metal-halide solar cells. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Sterol regulatory element-binding proteins are regulators of the sodium/iodide symporter in mammary epithelial cells.

Science.gov (United States)

Wen, G; Pachner, L I; Gessner, D K; Eder, K; Ringseis, R

2016-11-01

The sodium/iodide symporter (NIS), which is essential for iodide concentration in the thyroid, is reported to be transcriptionally regulated by sterol regulatory element-binding proteins (SREBP) in rat FRTL-5 thyrocytes. The SREBP are strongly activated after parturition and throughout lactation in the mammary gland of cattle and are important for mammary epithelial cell synthesis of milk lipids. In this study, we tested the hypothesis that the NIS gene is regulated also by SREBP in mammary epithelial cells, in which NIS is functionally expressed during lactation. Regulation of NIS expression and iodide uptake was investigated by means of inhibition, silencing, and overexpression of SREBP and by reporter gene and DNA-binding assays. As a mammary epithelial cell model, the human MCF-7 cell line, a breast adenocarcinoma cell line, which shows inducible expression of NIS by all-trans retinoic acid (ATRA), and unlike bovine mammary epithelial cells, is widely used to investigate the regulation of mammary gland NIS and NIS-specific iodide uptake, was used. Inhibition of SREBP maturation by treatment with 25-hydroxycholesterol (5 µM) for 48h reduced ATRA (1 µM)-induced mRNA concentration of NIS and iodide uptake in MCF-7 cells by approximately 20%. Knockdown of SREBP-1c and SREBP-2 by RNA interference decreased the mRNA and protein concentration of NIS by 30 to 50% 48h after initiating knockdown, whereas overexpression of nuclear SREBP (nSREBP)-1c and nSREBP-2 increased the expression of NIS in MCF-7 cells by 45 to 60%, respectively, 48h after initiating overexpression. Reporter gene experiments with varying length of NIS promoter reporter constructs revealed that the NIS 5'-flanking region is activated by nSREBP-1c and nSREBP-2 approximately 1.5- and 4.5-fold, respectively, and activation involves a SREBP-binding motif (SRE) at -38 relative to the transcription start site of the NIS gene. Gel shift assays using oligonucleotides spanning either the wild-type or the

Annual report for FY 1976 on project AN0115A: the migration of plutonium and americium in the lithosphere

International Nuclear Information System (INIS)

Fried, S.; Friedman, A.M.; Hines, J.J.; Atcher, R.W.; Quarterman, L.A.; Volesky, A.

1976-12-01

Studies have been carried out on the migration of plutonium and americium in solutions flowing through porous and crushed rock and through fissures. The migration process can be described in terms of the surface absorption of these elements. In addition, chemical effects on the absorption have been observed. One of these effects is possibly due to the presence of a plutonium polymer that migrates at a more rapid rate than normal plutonium

The uptake of plutonium-239, 240, americium-241, strontium-90 into plants

International Nuclear Information System (INIS)

Popplewell, D.S.; Ham, G.J.; Johnson, T.E.

1984-01-01

This report describes the results of measurements on the uptake of plutonium, americium, strontium-90 and caesium-137 into peas, beet, oats, sweet corn, tomatoes and vegetable marrow grown in tubs containing radioactively-contaminated silts. The silts had been taken from an area of West Cumbria commonly referred to as the Ravenglass estuary. The experiments are categorised as being carried out under non-standard conditions because of the manner in which the radioactivity came to be incorporated into the growth medium. The growth medium was representative of conditions which could arise when the estuarine silt moves inland under the influence of wind and tide and mixes with the adjacent farm land. The silt had been contaminated by radioactive effluents from the nuclear fuels reprocessing plant at Sellafield and this contamination had been brought about by natural means. (Auth.)

The synthesis of 1-11C-labelled ethyl, propyl, butyl and isobutyl iodides and examples of alkylation reactions

International Nuclear Information System (INIS)

Laangstroem, B.; Antoni, G.; Gullberg, P.; Halldin, C.; Naagren, K.; Rimland, A.; Svaerd, H.

1986-01-01

New 11 C-labelled precursors [1- 11 C]ethyl,[1- 11 C]propyl, [1- 11 C]butyl, and [1- 11 C]isobutyl iodides have been prepared by a 3-step reaction route using a one-pot system. The labelled iodides were obtained in 20-55#percent# radiochemical yields and 65-95#percent# radiochemical purities, with a total time for synthesis of the order of 10-14 min. The labelled iodides have been used in alkylation reactions with nitrogen, oxygen and carbon nucleophiles. The nitrogen alkylation reactions are exemplified by the synthesis of the analgetics N-[1- 11 C-ethyl]iodocaine and N-[1- 11 C-butyl] bupivacaine. The synthesis of 3-nitrophenyl[1- 11 C]propyl ether is also presented in this paper as an example of an oxygen alkylation. (author)

Leaching of iodine from composites based on epoxy resin and lead iodide

International Nuclear Information System (INIS)

Kalinin, N.N.; Elizarova, A.N.

1988-01-01

The scope for using solid composites obtained by incorporating dry powdery lead iodide and its aqueous suspension into epoxy resin for prolonged immobilization of iodine-129 under monitorable storage conditions has been assessed by a study of leaching of iodine

Nitro-Grela-type complexes containing iodides – robust and selective catalysts for olefin metathesis under challenging conditions

Directory of Open Access Journals (Sweden)

Andrzej Tracz

2015-10-01

Full Text Available Iodide-containing nitro-Grela-type catalysts have been synthesized and applied to ring closing metathesis (RCM and cross metathesis (CM reactions. These new catalysts have exhibited improved efficiency in the transformation of sterically, non-demanding alkenes. Additional steric hindrance in the vicinity of ruthenium related to the presence of iodides ensures enhanced catalyst stability. The benefits are most apparent under challenging conditions, such as very low reaction concentrations, protic solvents or with the occurrence of impurities.

Lymphocutaneous Sporotrichosis Treated with Potassium Iodide with Development of Subclinical Hypothyroidism: Wolff-Chaikoff Effect?

Science.gov (United States)

Arora, Pooja; Raihan, M; Kubba, Asha; Gautam, Ram K

2017-01-01

Sporotrichosis is a subcutaneous mycotic infection caused by Sporothrix schenckii that is acquired by traumatic implantation. The diagnosis is established by demonstration of fungal elements on histopathology and culture. Potassium iodide, azole antifungals, and terbinafine are the treatment options available. In this article, we report a 60-year-old female with lymphocutaneous sporotrichosis that responded well to potassium iodide. However, subclinical hypothyroidism (Wolff-Chaikoff effect) was encountered as a side effect of therapy which was managed with thyroxine replacement. Knowledge about the Wolff-Chaikoff effect (WCE) is important for the dermatologist and reinforces the need for screening and monitoring of thyroid stimulating hormone (TSH) in patients where long duration therapy is being planned.

Effects of trichostatin a on the expression of sodium/iodide symporter mRNA and the uptake of iodide in human thyroid cancer cell lines

International Nuclear Information System (INIS)

Bao Jiandong; Lin Xiufeng; Yu Huixin; Tan Cheng; Zhang Li

2010-01-01

Objective: To investigate the sodium/iodide symporter (NIS) expression and iodide uptake in thyroid cancer cells induced by the histone deacetyltransferase inhibitors (HDACi), Trichostatin A (TSA). Methods: Both the thyroid cancer cell lines, follicular thyroid carcinoma cell line FTC-133 and papillary thyroid carcinoma cell line K1, were firstly induced with TSA for 48 h. Then, the expression of NIS mRNA was analysed with reverse transcription-polymerase chain reaction (RT-PCR), the densitometric ratio of NIS/glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was calculated, and the iodide uptake in the thyroid cancer cells was also measured. Independent-sample t-test and one-way analysis of variance (ANOVA) were used to analyze the data. Results: For FTC-133 cells, increased NIS mRNA expression was detected after 48 h of TSA treatment, and the changes were dose-dependent (F=32.56, P 0.05). Furthermore, FTC-133 cells showed the ability of accumulating radioiodide with 50 and 75 nmol/L TSA induction for 48 h: (15.42 ± 0.42) x 10 3 counts · min -1 · 10 -5 cells vs (8.46 ± 0.84) x 10 3 counts · min -1 · 10 -5 cells, t=3.018, P 3 counts · min -1 · 10 -5 cells vs (8.46 ± 0.84) x 10 3 counts · min -1 · 10 -5 cells, t=3.557, P 3 counts · min -1 · 10 -5 cells, (6.97 ± 0.65) x 10 3 counts · min -1 · 10 -5 cells vs (5.37 ± 0.88) x 10 3 counts · min -1 · 10 -5 cells, t=0.185, P> 0.05 and t = 0.332, P > 0.05, respectively. Conclusion: TSA induced upregulated NIS mRNA expression in follicular thyroid cancer cells and augmented radioiodide uptake in thyroid cancer cells, while TSA had no remarkable effect on papillary thyroid carcinoma cell. (authors)

Determination of americium and curium using ion-exchange in the nitric-acid-methanol medium for environmental analysis

International Nuclear Information System (INIS)

Holm, E.; Fukai, R.

1976-01-01

While transplutonic elements are only slightly sorbed to anion exchangers from hydrochloric or nitric acid media, the presence of alcohol enhances the anionic exchange of these elements, especially in nitric and sulfuric solutions. In the present work a method has been developed for determining americium and curium in environmental samples, on the basis of the difference between the sorption characteristics to anion exchangers in the acid-methanol system of these transplutonic elements and those of plutonium, polonium and thorium. The method also permits us to perform sequential determination of plutonium, when necessary

Comparison of expressed human and mouse sodium/iodide sym-porters reveals differences in transport properties and subcellular localization

Energy Technology Data Exchange (ETDEWEB)

Dayem, M.; Basquin, C.; Navarro, V.; Carrier, P.; Marsault, R.; Lindenthal, S.; Pourcher, T. [Univ Nice Sophia Antipolis, Sch Med, CEA, DSV, iBEB, SBTN, TIRO, F-06107 Nice (France); Chang, P. [CNRS, UPMC Biol Dev, UMR 7009, F-06230 Villefranche Sur Mer (France); Huc, S.; Darrouzet, E. [CEA Valrho, DSV, iBEB, SBTN, F-30207 Bagnols Sur Ceze (France)

2008-07-01

The active transport of iodide from the blood stream into thyroid follicular cells is mediated by the Na{sup +}/I{sup -} sym-porter (NIS). We studied mouse NIS (mNIS) and found that it catalyzes iodide transport into transfected cells more efficiently than human NIS (hNIS). To further characterize this difference,we compared {sup 125}I, uptake in the transiently transfected human embryonic kidney (HEK) 293 cells. We found that the Vmax for mNIS was four times higher than that for hNIS, and that the iodide transport constant (Km) was 2-5-fold lower for hNIS than mNIS. We also performed immuno-cyto-localization studies and observed that the subcellular distribution of the two ortho-logs differed. While the mouse protein was predominantly found at the plasma membrane, its human ortho-log was intracellular in {approx} 40% of the expressing cells. Using cell surface protein-labeling assays, we found that the plasma membrane localization frequency of the mouse protein was only 2-5-fold higher than that of the human protein, and therefore cannot alone account for,x values. We reasoned that the difference in the obtained Vmax the observed difference could also be caused by a higher turnover number for iodide transport in the mouse protein. We then expressed and analyzed chimeric proteins. The data obtained with these constructs suggest that the iodide recognition site could be located in the region extending from the N-terminus to transmembrane domain 8, and that the region between transmembrane domain 5 and the C-terminus could play a role in the subcellular localization of the protein. (authors)

Comparison of expressed human and mouse sodium/iodide sym-porters reveals differences in transport properties and subcellular localization

International Nuclear Information System (INIS)

Dayem, M.; Basquin, C.; Navarro, V.; Carrier, P.; Marsault, R.; Lindenthal, S.; Pourcher, T.; Chang, P.; Huc, S.; Darrouzet, E.

2008-01-01

The active transport of iodide from the blood stream into thyroid follicular cells is mediated by the Na + /I - sym-porter (NIS). We studied mouse NIS (mNIS) and found that it catalyzes iodide transport into transfected cells more efficiently than human NIS (hNIS). To further characterize this difference,we compared 125 I, uptake in the transiently transfected human embryonic kidney (HEK) 293 cells. We found that the Vmax for mNIS was four times higher than that for hNIS, and that the iodide transport constant (Km) was 2-5-fold lower for hNIS than mNIS. We also performed immuno-cyto-localization studies and observed that the subcellular distribution of the two ortho-logs differed. While the mouse protein was predominantly found at the plasma membrane, its human ortho-log was intracellular in ∼ 40% of the expressing cells. Using cell surface protein-labeling assays, we found that the plasma membrane localization frequency of the mouse protein was only 2-5-fold higher than that of the human protein, and therefore cannot alone account for,x values. We reasoned that the difference in the obtained Vmax the observed difference could also be caused by a higher turnover number for iodide transport in the mouse protein. We then expressed and analyzed chimeric proteins. The data obtained with these constructs suggest that the iodide recognition site could be located in the region extending from the N-terminus to transmembrane domain 8, and that the region between transmembrane domain 5 and the C-terminus could play a role in the subcellular localization of the protein. (authors)

Administration of additional inactive iodide during radioiodine therapy for Graves' disease. Who might benefit?

International Nuclear Information System (INIS)

Dietlein, M.; Moka, D.; Reinholz, U.; Schmidt, M.; Schomaecker, K.; Schicha, H.; Wellner, U.

2007-01-01

Aim: Graves' hyperthyroidism and antithyroid drugs empty the intrathyroid stores of hormones and iodine. The consequence is rapid 131 I turnover and impending failure of radioiodine therapy. Can administration of additional inactive iodide improve 131I kinetics? Patients, methods: Fifteen consecutive patients, in whom the 48 h post-therapeutically calculated thyroid dose was between 150 and 249 Gy due to an unexpectedly short half-life, received 3 x 200 μg inactive potassium-iodide ( 127 I) daily for 3 days (Group A), while 17 consecutive patients with a thyroid dose of = 250 Gy (Group B) served as the non-iodide group. 48 hours after 131 I administration (M1) and 4 or 5 days later (M2) the following parameters were compared: effective 131 I half-life, thyroid dose, total T3, total T4, 131 I-activity in the T3- and T4-RIAs. Results: In Group A, the effective 131 I half-life M1 before iodine (3.81 ± 0.93 days) was significantly (p 131 I half-life M2 (4.65 ± 0.79 days). Effective 131 I half-life M1 correlated with the benefit from inactive 127 I (r = -0.79): Administration of 127 I was beneficial in patients with an effective 131 I half-life M1 of 131 I activity of T3 and T4 showed lower specific 131 I activity after addition of inactive iodine compared with patients from the same group with a lower initial specific 131 I activity of T3 and T4 and compared with the patient group B who was given no additional inactive iodide. This correlation was mathematically described and reflected in the flatter gradient in Group A (y = 0.5195x + 0.8727 for 131 I T3 and y = 1.0827x - 0.4444 for 131 I T4) and steeper gradient for Group B (y = 0.6998x + 0.5417 for 131 I T3 and y = 1.3191x - 0.2901 for 131 I T4). Radioiodine therapy was successful in all 15 patients from Group A. Conclusion: The administration of 600 μg inactive iodide for three days during radioiodine therapy in patients with Graves' hyperthyroidism and an unexpectedly short half-life of <3 or 4 days was a safe

Oxidation of iodide and iodine on birnessite (delta-MnO2) in the pH range 4-8.

Science.gov (United States)

Allard, Sébastien; von Gunten, Urs; Sahli, Elisabeth; Nicolau, Rudy; Gallard, Hervé

2009-08-01

The oxidation of iodide by synthetic birnessite (delta-MnO(2)) was studied in perchlorate media in the pH range 4-8. Iodine (I(2)) was detected as an oxidation product that was subsequently further oxidized to iodate (IO(3)(-)). The third order rate constants, second order on iodide and first order on manganese oxide, determined by extraction of iodine in benzene decreased with increasing pH (6.3-7.5) from 1790 to 3.1M(-2) s(-1). Both iodine and iodate were found to adsorb significantly on birnessite with an adsorption capacity of 12.7 microM/g for iodate at pH 5.7. The rate of iodine oxidation by birnessite decreased with increasing ionic strength, which resulted in a lower rate of iodate formation. The production of iodine in iodide-containing waters in contact with manganese oxides may result in the formation of undesired iodinated organic compounds (taste and odor, toxicity) in natural and technical systems. The probability of the formation of such compounds is highest in the pH range 5-7.5. For pH iodine is quickly oxidized to iodate, a non-toxic and stable sink for iodine. At pH >7.5, iodide is not oxidized to a significant extent.

Determination of radiation dose rates and urinary activity of patients received Sodium Iodide-131 for treatment of differentiated thyroid carcinoma

International Nuclear Information System (INIS)

Beiki, D.; Shahhosseini, S.; Dadashzadeh, S.; Eftekhari, M.; Tayebi, H.; Moosazadeh-Rashti, G.

2004-01-01

Sodium Iodide-131 is administrated for treatment of hyperthyroidism and thyroid cancer. Iodine-131 has multiple routs of excretion (urine, saliva, sweat, milk, feces, exhalation) from the body. Patients receiving Sodium Iodide-131 therapy exposes other persons and the environment to unwanted radiation and contamination. The major sources of radiation dose from administration of Iodine-131 is external radiation , also there is a potential for exposure via contamination.Precautions are necessary to limit the radiation dose to family members, nursing staff and members of public and waste treatment workers to less than 1mSv. Patients received Sodium Iodide-131 may come into close contact with other persons. In order to derive appropriate recommendations, dose rates were measured from the anterior mid-trunk of 29 patients in the upright position with 15 minutes post-dose administration at 3 meters and just before they left the nuclear medicine department at 0.5, 1, and 3 meters. We have also measured urinary iodide excretion in 29 patients to estimate Sodium Iodide-131 urinary excretion pattern in iranian patients. Based on results, the maximum cumulative dose to nursing staff was on third day (leaving day) still less than recommended dose bye ICRP. The cumulative dose family members will be more but regarding the time and distance in close contact it will be also less than recommended dose by ICRP.Radiation dose rate was decreased significantly on third day. The urinary excretion patterns in all patients were similar. The urinary excretion rate-time curve in all patients showed multiple peaks due to retention and redistribution of Iodine-131 or enterohepatic cycle of radioiodinated thyroid hormones, which didn't allow calculation of urinary excretion rate constant. The results also showed that 67 hours post administration of Sodium Iodide-131 about 70% of radiopharmaceutical was excreted through urine, 28% physically decayed or eliminated through other biological

Contribution to the study of pseudohalides complexes of tervalent, lanthanides and actinides in solution

International Nuclear Information System (INIS)

Cuillerdier, Christine.

1981-10-01

Some complexes formed with halides or pseudohalides (iodide, cyanide, azide and thiocyanate) and tervalent lanthanides and actinides have been studied in solution. Methods like solvent extraction, polarography have been used to measure inner plus outer sphere complexation and spectroscopic methods have been chosen to study inner sphere complexes only. It has been found that inner sphere complexe of americium and neodymium with cyanide exist in aqueous solutions. Tervalent actinides form stronger inner sphere complexes with azide than lanthanide in solution. Thiocyanate complexes appear to be inner sphere and N-bonded [fr

Synthesis of 1-/sup 11/C-labelled ethyl, propyl, butyl and isobutyl iodides and examples of alkylation reactions

Energy Technology Data Exchange (ETDEWEB)

Laangstroem, B.; Antoni, G.; Gullberg, P.; Halldin, C.; Naagren, K.; Rimland, A.; Svaerd, H.

1986-01-01

New /sup 11/C-labelled precursors (1-/sup 11/C)ethyl,(1-/sup 11/C)propyl, (1-/sup 11/C)butyl, and (1-/sup 11/C)isobutyl iodides have been prepared by a 3-step reaction route using a one-pot system. The labelled iodides were obtained in 20-55% radiochemical yields and 65-95% radiochemical purities, with a total time for synthesis of the order of 10-14 min. The labelled iodides have been used in alkylation reactions with nitrogen, oxygen and carbon nucleophiles. The nitrogen alkylation reactions are exemplified by the synthesis of the analgetics N-(1-/sup 11/C-ethyl)iodocaine and N-(1-/sup 11/C-butyl) bupivacaine. The synthesis of 3-nitrophenyl(1-/sup 11/C)propyl ether is also presented in this paper as an example of an oxygen alkylation.

Polarographic determination of Iodide and Iodate, in Solutions Coming from Aerosols in Fission Products Containment Studies in Nuclear Power Stations

International Nuclear Information System (INIS)

Sanchez, M.; Ballesteros, O.; Fernandez, M.; Clavero, M.A.; Gonzalez, A.M.

2000-01-01

A polarographic method is described for the iodine species determination, iodide and iodate in water solutions. the iodate can be determined by differential pulse polarography. Calibration curves and the detection and determination limits have been obtained. Iodides is oxidized to iodate with sodium hypochlorite and the excess of oxidizing agent is destroyed with sodium sulphide. The concentration of iodide is calculated as the difference between the concentration of iodate in the sample before and after the oxidation. As an application, species of iodine in samples coming from the experimental plants GIRS (Gaseous Iodine Removal by Sprays) of Nuclear Fission Department of the CIEMAT, dedicated to fission products containment studies in nuclear power station, were determined. (Author) 10 refs

Solution enthalpy of potassium iodide in furfural and its mixtures with dimethylsulfoxide

International Nuclear Information System (INIS)

Vlasenko, K.K.; Belov, A.A.; Vorob'ev, A.F.

1986-01-01

Solution enthalpy of potassium iodide in furfural-dimethylsulfoxide mixtures at 298.15 K and furfural concentration 17.3-100% are determined experimentally. K + and I - ion solvate shell composition, which in the general case doesn't correspond to the mixed solvent composition, is calculated

Sensitive determination of iodide in the presence of large quantities of chloride

International Nuclear Information System (INIS)

Hainberger, L.; Lenzi, E.

1982-01-01

A determination of iodide with catalytic oxidation of p-phenetidine is described. A dye is formed with a maximum of absorption at 490 nm. The law of Lambert-Beer is obeyed between 0.6 and 2.2 ppm. Some of the interferents are examined. (Author)

The MARINE experiment: Irradiation of sphere-pac fuel and pellets of UO{sub 2−x} for americium breeding blanket concept

Energy Technology Data Exchange (ETDEWEB)

D' Agata, E., E-mail: elio.dagata@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Hania, P.R. [Nuclear Research and Consultancy Group, P.O. Box 25, NL-1755 ZG Petten (Netherlands); Freis, D.; Somers, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Bejaoui, S. [Commissariat à l’Energie Atomique et aux Energies Alternatives, DEN/DEC, F-13108 St. Paul lez Durance Cedex (France); Charpin, F.F.; Baas, P.J.; Okel, R.A.F.; Til, S. van [Nuclear Research and Consultancy Group, P.O. Box 25, NL-1755 ZG Petten (Netherlands); Lapetite, J.-M. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Delage, F. [Commissariat à l’Energie Atomique et aux Energies Alternatives, DEN/DEC, F-13108 St. Paul lez Durance Cedex (France)

2017-01-15

Highlights: • MARINE is designed to check the behaviour of MABB sphere-pac concept. • MABB sphere-pac are compared with MABB pellet. • Swelling and helium release behaviour will be the main output of the experiment. • An experiment to check sphere-pac MADF fuel behaviour has been already performed. - Abstract: Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors of long-lived nuclides like {sup 241}Am is therefore an option for the reduction of radiotoxicity and heat production of waste packages to be stored in a repository. The MARINE irradiation experiment is the latest of a series of European experiments on americium transmutation (e.g. EFTTRA-T4, EFTTRA-T4bis, HELIOS, MARIOS, SPHERE) performed in the High Flux Reactor (HFR). The MARINE experiment is developed and carried out in the framework of the collaborative research project PELGRIMM of the EURATOM 7th Framework Programme (FP7). During the past years of experimental works in the field of transmutation and tests of innovative nuclear fuels, the release or trapping of helium as well as swelling have been shown to be the key issues for the design of such kind of fuel both as drivers and even more for Am-bearing blanket targets (due to the higher Am contents). The main objective of the MARINE experiment is to study the in-pile behaviour of uranium oxide fuel containing 13% of americium and to compare the behaviour of sphere-pac versus pellet fuel, in particular the role of microstructure and temperature on fission gas release and He on fuel swelling. The MARINE experiment will be irradiated in 2016 in the HFR in Petten (The Netherlands) and is expected to be completed in spring 2017. This paper discusses the rationale and objective of the MARINE experiment and provides a general description of its design for which some innovative features have been adopted.

Preparation of an ultra-fine, slightly dispersed silver iodide aerosol

International Nuclear Information System (INIS)

Poc, Marie-Martine

1973-01-01

A silver iodide aerosol was prepared under clean conditions. The method was to react iodine vapor with a silver aerosol in an inert dry atmosphere and in darkness. Great care was taken to avoid contamination from atmosphere air. The ice nucleating properties of the ultrafine AgI aerosol obtained were studied in a cloud mixing chamber: the aerosol was found to be strangely inactive. (author) [fr

Crystal growth and characterization of europium doped lithium strontium iodide scintillator as an ionizing radiation detector

Science.gov (United States)

Uba, Samuel

High performance detectors used in the detection of ionizing radiation is critical to nuclear nonproliferation applications and other radiation detectors applications. In this research we grew and tested Europium doped Lithium Strontium Iodide compound. A mixture of lithium iodide, strontium iodide and europium iodide was used as the starting materials for this research. Congruent melting and freezing temperature of the synthesized compound was determined by differential scanning calorimetry (DSC) using a Setaram Labsys Evo DSC-DTA instrument. The melting temperatures were recorded at 390.35°C, 407.59°C and freezing temperature was recorded at 322.84°C from a graph of heat flow plotted against temperature. The synthesized material was used as the charge for the vertical Bridgeman growth, and a 6.5 cm and 7.7cm length boule were grown in a multi-zone transparent Mullen furnace. A scintillating detector of thickness 2.53mm was fabricated by mechanical lapping in mineral oil, and scintillating response and timing were obtained to a cesium source using CS-137 isotope. An energy resolution (FWHM over peak position) of 12.1% was observed for the 662keV full absorption peak. Optical absorption in the UV-Vis wavelength range was recorded for the grown crystal using a U-2900 UV/VIS Spectrophotometer. Absorption peaks were recorded at 194nm, 273nm, and 344nm from the absorbance spectrum, various optical parameters such as absorption coefficient, extinction coefficient, refractive index, and optical loss were derived. The optical band gap energy was calculated using Tauc relation expression at 1.79eV.

Measurements of rates of some reactions related to radiolytic effect on aqueous iodide solution

International Nuclear Information System (INIS)

Shiraishi, H.; Okuda, H.; Ishigure, K.

1986-01-01

A number of reactions takes place concurrently when aqueous iodide solution is subjected to radiation field. In order to help analyze this complicated radiation effect measurements of rate constants were undertaken for several important reactions. One of these concerns reduction of hypoiodous acid by hydrogen peroxide. For this reaction catalytic effect was found to be significant, and old rate data was revised. Measurements on reactions involving radicals were carried out by use of pulse radiolysis technique, which also include reexamination of results by previous workers. The reactions studied are (1) oxidation of iodide ion by hydroxyl radical (2) recombination reactions of atomic iodine and diiodide ion and (3) reduction of atomic and molecular iodine either by superoxide ion or by hydroperoxyl radical

Performance of non-coconut base adsorbers in removal of iodine and organic iodides

International Nuclear Information System (INIS)

Rivers, R.D.; Pasha, M.; Fowler, E.E.; Goldsmith, J.M.

1975-01-01

Systems for the removal of radioactive iodine and organic iodides have used impregnated coconut shell activated carbons almost exclusively. Coconut shell carbons have some disadvantages: their geographical origin determines their trace chemical content; pore structures and impregnant effectiveness are highly dependent on activation and impregnation techniques. The authors report laboratory performance of a group of iodine-organic iodide adsorbers using bases other than coconut shell carbon. These have been evaluated in conformity with USAEC Regulatory Guide 1.52 and RDT M16 1T. Performance with regard to 131 I 2 and CH 3 131 I penetration and high-temperature elution have equaled or exceeded both the requirements of Guide 1.52 and results on typical coconut-shell carbons. Some performance outside Guide 1.52 ranges is included. Experimental problems in simulated LOCA testing are discussed. (U.S.)

Kinetic and Mechanistic Aspects of the Reactions of Iodide and Hypoiodous Acid with Permanganate: Oxidation and Disproportionation.

Science.gov (United States)

Zhao, Xiaodan; Salhi, Elisabeth; Liu, Huiling; Ma, Jun; von Gunten, Urs

2016-04-19

Oxidation kinetics of iodide and HOI/OI(-) by permanganate were studied in the pH range of 5.0-10.0. Iodide oxidation and iodate formation were faster at lower pH. The apparent second-order rate constants (k(obs)) for iodide oxidation by permanganate decrease with increasing pH from 29 M(-1) s(-1) at pH 5.0 and 6.9 M(-1) s(-1) at pH 7.0 to 2.7 M(-1) s(-1) at pH 10.0. k(obs) for HOI abatement are 56 M(-1) s(-1) at pH 5.0, 2.5 M(-1) s(-1) at pH 7.0, and 173 M(-1) s(-1) at pH 10.0. Iodate yields over HOI abatement decrease from 98% at pH 6.0 to 33% for pH ≥ 9.5, demonstrating that HOI disproportionation dominates HOI transformation by permanganate at pH ≥ 8.0. MnO2 formed as a product from permanganate reduction, oxidizes HOI to iodate for pH oxidation or disproportionation induced by MnO2 is much lower than for permanganate. During treatment of iodide-containing waters, the potential for iodinated disinfection byproducts (I-DBPs) formation is highest at pH 7.0-8.0 due to the long lifetime of HOI. For pH oxidized by permanganate to iodate, whereas for pH ≥ 8.0, HOI/OI(-) undergoes a fast permanganate-mediated disproportionation.

Production of high quality sodium iodide preparations labelled with carrier free iodine-125

International Nuclear Information System (INIS)

Abdukayumov, M.N.; Chistyakov, P.G.; Shilin, E.A.

2001-01-01

Work is related to the problem of high-quality Sodium Iodide preparation production and to the choice of the peptids iodination methods with the purpose of control test developing to determine the Biological activity of the above mentioned preparation

1-(Ferrocen-1-ylmethyl-3-methylimidazol-3-ium iodide

Directory of Open Access Journals (Sweden)

Vincent O. Nyamori

2012-12-01

Full Text Available The structure of the title compound, [Fe(C5H5(C10H12N2]I, consists of a 1-(ferrocen-1-ylmethyl-3-methylimidazolium cation which is counter-balanced by an iodide anion. The cyclopentadienyl (Cp rings of the ferrocene unit have a slightly staggered conformation skewed from an ideal eclipsed conformation by an angle of 3.5 (6°. The interplanar angle between the Cp and the imidazole ring is 67.94 (2°.

Film formation of non-planar phthalocyanines on copper(i) iodide

OpenAIRE

Ramadan, A. J.; Fearn, S.; Jones, T. S. (Tim S.); Heutz, S.; Rochford, L. A. (Luke A.)

2016-01-01

Structural templating is frequently used in organic photovoltaic devices to control the properties of the functional layers and therefore improve efficiencies. Modification of the substrate temperatures has also been shown to impact the structure and morphology of phthalocyanine thin films. Here we combine templating by copper iodide and high substrate temperature growth and study its effect on the structure and morphology of two different non-planar phthalocyanines, chloroaluminium (ClAlPc) ...

Rapid sonochemical preparation of shape-selective lead iodide

International Nuclear Information System (INIS)

Huang, Baojun; He, Qin; Fa, Wenjun; Li, Pinjiang; Zhang, Yange; Zheng, Zhi

2012-01-01

Graphical abstract: SEM morphologies of various PbI2 products obtained with the iodine concentration of 6.7 g/L and irradiation time of 1 minute at the reaction temperatures of 35 °C (a), 25 °C (b), and 15 °C (c). Highlights: ► PbI 2 with various morphologies were rapidly formed at room temperature. ► We could well control the morphologies of PbI 2 by changing reaction conditions. ► The PbI 2 films could better resist rolling in a liquid media. -- Abstract: Lead iodide (PbI 2 ) films/crystals with various nano/micro morphologies (e.g., Nanoflake, block and microrod) were rapidly synthesized by taking advantage of a simple sonochemical method. The PbI 2 crystals with uniform nanoflake structures could be fabricated directly on lead foils with the irradiation time as short as 36 s via interfacial reaction between lead foils and elemental iodine in ethanol at ambient temperature. It was found experimentally that the morphologies of the resulting thin films/crystals could be well controlled by the adjustment of several parameters including irradiation time, reaction solvents, iodine concentration, ultrasonic power, and reaction temperature. Most importantly, the resultant PbI 2 films are stable enough to resist rolling under the drastic ultrasound irradiation in a liquid media. This method is believed to be the fastest way for in situ fabrication of morphology-controlled semiconductor films on various metal substrates for subsequent applications related to the other metal iodide or metal sulfide semiconductor films.

A comparison between the secretion of Tc-99m pertechnetate and I-131 iodide through the stomach of the chacma monkey

International Nuclear Information System (INIS)

Ellmann, A.

1985-03-01

The way in which pertechnetate is excreted by the stomach is a continuing controversy in the nuclear medicine literature. The question arises: Does the stomach, unlike the thyroid handle pertechnetate and iodide by different mechanisms? The excretion of pertechnetate and iodide by the stomach in the Chacma baboon was compared. In this way an attempt was made to obtain more information on the way in which the stomach handles pertechnetate. The study was performed on young adult Chacma baboons. Pertechnetate and iodide were administeed simultaneously via the intravenous route. 6 Baboons were studied after pharmacological interventions, namely the administration of pentagastrin, cimetidine and perchlorate. Nine other baboons were studied after surgical interventions. Three groups of 3 each were studied after selective vagotomy, Billroth I gastrectomy and proximal gastrectomy respectively. In the surgical group post-operative studies were also done before and after pentagastrin stimulation. Tissue samples of the stomachs of 4 baboons were studied. The various types of surgery all resulted in a decrease in the volume of gastric juice. The excretion of pertechnetate and iodide was related to the volume of gastric juice except after the administration of perchlorate. In spite of marked changes of up to 60 times in the amount of pertechnetate and iodide excretion after the pharmacological and surgical interventions, the Tc : I - ratio remained almost constant. The Tc : I - ratio in the blood samples showed a gradual increase as could be expected. The Tc : I - ratios in the tissue samples were similar to those in the blood samples. It is indicated that, like iodide, pertechnetrat is probably excreted by the mucus cells of the stomach and not by the parietal cells. 28 figs., 164 refs., 6 tabs

Theoretical investigation of pressure-induced structural transitions in americium using GGA+U and hybrid density functional theory methods

DEFF Research Database (Denmark)

Verma, Ashok K.; Modak, P.; Sharma, Surinder M.

2013-01-01

First-principles calculations have been performed for americium (Am) metal using the generalized gradient approximation + orbital-dependent onsite Coulomb repulsion via Hubbard interaction (GGA+U) and hybrid density functional theory (HYB-DFT) methods to investigate various ground state properties......-I to Am-II transition. Good agreement was found between calculated and experimental equations of states for all phases, but the first three phases need larger U (α) parameters (where α represents the fraction of Hartree-Fock exchange energy replacing the DFT exchange energy) than the fourth phase in order...

Performance test of silver ion-exchanged zeolite for the removal of gaseous radioactive methyl iodide at high temperature condition

International Nuclear Information System (INIS)

Byung-Seon Choi; Geun-Il Park; Jung-Won Lee; Ho-Yeon Yang; Seung-Kon Ryu

2003-01-01

Performance tests of silver ion-exchanged zeolite (AgX) adsorbent for the control of radioiodine gas generated from a high-temperature process were carried out using both non-radioactive and a radioactive methyl iodide tracers. From the identification of SEM-EDAX analysis, an experimental result of silver ion-exchanged ratio containing 10∼30 wt% of Ag was fit to that calculated by the weight increment, and it was confirmed that the silver was uniformly distributed inside the pores of the adsorbent. Demonstration test of AgX-10 adsorbent using radioactive methyl iodide tracer was performed. The removal efficiency of radioiodine with AgX-10 in the temperature ranges of 150 to 300 deg C was in the ranges of 99.9% to 99.99%, except for 300 deg C. The influence of the long-term weathering and the poisoning with NO 2 gas (200 ppm) on adsorption capacity of AgX-10 was also analyzed. The removal efficiency of radioactive methyl iodide by AgX-10 weathered for 14 weeks was 99.95%. Long-term poisoning test showed that the adsorption efficiency of methyl iodide started to decrease after 10 weeks, and the removal efficiency of radioiodine by AgX-10, poisoned for 16 weeks, was 99% (DF=100). (author)

Mercuric iodide sensor technology

International Nuclear Information System (INIS)

James, R.B.; Anderson, R.J.; Schlesinger, T.E.

1996-09-01

This report describes the improvement in the performance and the manufacturing yield of mercuric iodide detectors achieved by identifying the dominant impurities, carrier traps, and processing steps limiting device performance. Theoretical studies of electron and hole transport in this material set fundamental limits on detector performance and provided a standard against which to compare experimental results. Spectroscopy techniques including low temperature photoluminescence and thermally stimulated current spectroscopy were applied to characterize the deep level traps in this material. Traps and defects that can be introduced into the detector during growth, from the contact, and during the various steps in detector fabrication were identified. Trap energy levels and their relative abundances were determined. Variations in material quality and detector performance at the micron scale were investigated to understand the distribution in electric field in large volume detectors suitable for gamma-ray spectroscopy. Surface aging and contact degradation was studied extensively by techniques including atomic force microscopy, transmission electron microscopy, and variable angle spectroscopic ellipsometry. Preferred handling and processing procedures for maximizing detector performance and yield were established. The manufacturing yield of high resolution gamma-ray detectors was improved from a few percent to more than 30%

Preparation of curium-americium oxide microspheres by resin-bead loading

International Nuclear Information System (INIS)

Chattin, F.R.; Benker, D.E.; Lloyd, M.H.; Orr, P.B.; Ross, R.G.; Wiggins, J.T.

1980-01-01

Resin-bead loading and calcination techniques have been used to produce all curium and americium oxide feed material (about 2.2 kg) for HFIR targets since 1971. The process based on Dowex 50W resin has progressed from a series of test runs, through special production runs, into routine production in permanent equipment beginning in 1975. Key attributes of this process are its reliability, high yields, and ease of operation. The process is suited for remote operation in hot cells. Yields approaching 95% are routinely obtained and only one unacceptable product has been generated during routine production operations. There have been no problems in fabricating targets from this oxide or in the subsequent irradiation of these targets. The present scale of production of 150 to 250 g/y supplies the present need and is comparable with the level of other chemical process operations at TRU. Since the annual production is accomplished in two 8 to 12 day periods, there has been no reason to consider further scale-up. However, the rate of production could easily be doubled by simply adding a second set of calcination equipment

Gap energy studied by optical transmittance in lead iodide monocrystals grown by Bridgman's Method

Directory of Open Access Journals (Sweden)

Veissid N.

1999-01-01

Full Text Available The bandgap energy as a function of temperature has been determined for lead iodide. The monocrystal was obtained in a vacuum sealed quartz ampoule inside a vertical furnace by Bridgman's method. The optical transmittance measurement enables to evaluate the values of Eg. By a fitting procedure of Eg as a function of temperature is possible to extract the parameters that govern its behavior. The variation of Eg with temperature was determined as: Eg(T = Eg(0 - aT2/(a + T, with: Eg(0 = (2.435 ± 0.008 eV, a = (8.7 ± 1.3 x 10-4 eV/K and a = (192 ± 90 K. The bandgap energy of lead iodide at room temperature was found to be 2.277 ± 0.007 eV.

Phase Stability and Electronic Structure of Prospective Sb-Based Mixed Sulfide and Iodide 3D Perovskite (CH3NH3)SbSI2.

Science.gov (United States)

Li, Tianyang; Wang, Xiaoming; Yan, Yanfa; Mitzi, David B

2018-06-29

Lead-free antimony-based mixed sulfide and iodide perovskite phases have recently been reported to be synthesized experimentally and to exhibit reasonable photovoltaic performance. Through a combination of experimental validation and computational analysis, we show no evidence of the formation of the mixed sulfide and iodide perovskite phase, MASbSI 2 (MA = CH 3 NH 3 + ), and instead that the main products are a mixture of the binary and ternary compounds (Sb 2 S 3 and MA 3 Sb 2 I 9 ). Density functional theory calculations also indicate that such a mixed sulfide and iodide perovskite phase should be thermodynamically less stable compared with binary/ternary anion-segregated secondary phases and less likely to be synthesized under equilibrium conditions. Additionally, band structure calculations show that this mixed sulfide and iodide phase, if possible to synthesize (e.g., under nonequilibrium conditions), should have a suitable direct band gap for photovoltaic application.

The influence of sodium salts (iodide, chloride and sulfate) on the formation efficiency of sulfamerazine nanocrystals.

Science.gov (United States)

Lou, Hao; Liu, Min; Qu, Wen; Johnson, James; Brunson, Ed; Almoazen, Hassan

2014-08-01

The purpose of this study is to evaluate the influence of sodium iodide, sodium chloride and sodium sulfate on the formation efficiency of sulfamerazine nanocrystals by wet ball milling. Sulfamerazine was milled using zirconium oxide beads in a solution containing polyvinylpyrrolidone (PVP) and a sodium salt (iodide, chloride or sulfate). Particle size distributions were evaluated by light diffraction before and after milling. High-performance liquid chromatography was utilized to determine the amount of PVP adsorbed onto sulfamerazine surface. Lyophilized nanocrystals were further characterized by differential scanning calorimetry and dissolution testing. Sulfate ion had more profound effect on reducing particle size via milling than iodide or chloride. We linked our findings to Hofmeister ion series, which indicates that sulfate ions tends to break the water structure, increases the surface tension and lowers the solubility of hydrocarbons in water. We hypothesized that the addition of sulfate ions dehydrated the PVP molecules and enhanced its adsorption onto the sulfamerazine particle surfaces. Consequently, the adsorbed PVP helped to stabilize of the nanosuspension. The nanocrystals that were obtained from the lyophilized milled suspensions exhibited a notable increase in dissolution rate. The addition of sodium sulfate enhanced the formation efficiency of sulfamerazine nanocrystals.

Separation of americium by liquid-liquid extraction using diglycol-amides water-soluble complexing agents

Energy Technology Data Exchange (ETDEWEB)

Chapron, S.; Marie, C.; Pacary, V.; Duchesne, M.T.; Miguirditchian, M. [CEA, Centre de Marcoule, Nuclear Energy Division, RadioChemistry and Processses Departement, 30207 Bagnols-sur-Ceze (France); Arrachart, G.; Pellet-Rostaing, S. [Institut de Chimie Separative de Marcoule, LTSM, Bat 426, F-30207 Bagnols-sur- Ceze (France)

2016-07-01

Recycling americium (Am) alone from spent nuclear fuels is an important option studied for the future nuclear cycle (Generation IV systems) since Am belongs to the main contributors of the long-term radiotoxicity and heat power of final waste. Since 2008, a liquid-liquid extraction process called EXAm has been developed by the CEA to allow the recovery of Am alone from a PUREX raffinate (a dissolution solution already cleared from U, Np and Pu). A mixture of DMDOHEMA (N,N'-dimethyl-N,N'-dioctyl-2-(2-(hexyloxy)ethyl)-malonamide) and HDEHP (di-2-ethylhexylphosphoric acid) in TPH is used as the solvent and the Am/Cm selectivity is improved using TEDGA (N,N,N',N'-tetraethyl-diglycolamide) as a selective complexing agent to maintain Cm and heavier lanthanides in the acidic aqueous phase (5 M HNO{sub 3}). Americium is then stripped selectively from light lanthanides at low acidity (pH=3) with a poly-aminocarboxylic acid. The feasibility of sole Am recovery was already demonstrated during hot tests in ATALANTE facility and the EXAm process was adapted to a concentrated raffinate to optimize the process compactness. The speciation of TEDGA complexes formed in the aqueous phase with Am, Cm and lanthanides was studied to better understand and model the behavior of TEDGA in the process. Some Ln-TEDGA species are extracted into the organic phase and this specific chemistry might play a role in the Am/Cm selectivity improvement. Hence the hydrophilicity-lipophilicity balance of the complexing agent is an important parameter. In this comprehensive study, new analogues of TEDGA were synthesized and tested in the EXAm process conditions to understand the relationship between their structure and selectivity. New derivatives of TEDGA with different N-alkyl chain lengths and ramifications were synthesized. The impact of lipophilicity on ligand partitioning and Am/Cm selectivity was investigated. (authors)

Assessment of radiation doses from residential smoke detectors that contain americium-241

International Nuclear Information System (INIS)

O'Donnell, F.R.; Etnier, E.L.; Holton, G.A.; Travis, C.C.

1981-10-01

External dose equivalents and internal dose commitments were estimated for individuals and populations from annual distribution, use, and disposal of 10 million ionization chamber smoke detectors that contain 110 kBq (3 μCi) americium-241 each. Under exposure scenarios developed for normal distribution, use, and disposal using the best available information, annual external dose equivalents to average individuals were estimated to range from 4 fSv (0.4 prem) to 20 nSv (2 μrem) for total body and from 7 fSv to 40 nSv for bone. Internal dose commitments to individuals under post disposal scenarios were estimated to range from 0.006 to 80 μSv (0.0006 to 8 mrem) to total body and from 0.06 to 800 μSv to bone. The total collective dose (the sum of external dose equivalents and 50-year internal dose commitments) for all individuals involved with distribution, use, or disposal of 10 million smoke detectors was estimated

Simultaneous determination of bromide and iodide as acetone derivatives by gas chromatography and electron capture detection in natural waters and biological fluids

International Nuclear Information System (INIS)

Maros, L.; Kaldy, M.; Igaz, S.

1989-01-01

Oxidation of bromide and iodide ions in acidic solutions in the presence of acetone forms the corresponding acetone derivatives. Iodate was reduced with thiosulfate prior to the determination. After extraction with benzene the bromo- and iodoacetone were measured by gas chromatography using electron capture detection. The bromide and iodide contents of rainwater, drinking water, river water, seawater, oil brine, common salt, cow milk, and human blood serum were determined. The relative standard deviations for bromide at 10/sup /minus/7/ M and for iodide at 10/sup /minus/8/ M concentration were 1.9% and 3.0%, respectively, using 10-mL sample for the determination without preconcentration

Capture of organic iodides from nuclear waste by metal-organic framework-based molecular traps

KAUST Repository

Li, Baiyan; Dong, Xinglong; Wang, Hao; Ma, Dingxuan; Tan, Kui; Jensen, Stephanie; Deibert, Benjamin J.; Butler, Joseph; Cure, Jeremy; Shi, Zhan; Thonhauser, Timo; Chabal, Yves J.; Han, Yu; Li, Jing

2017-01-01

capture from nuclear waste. The capture mechanism was investigated by experimental and theoretical methods.Capturing radioactive organic iodides from nuclear waste is important for safe nuclear energy usage, but remains a significant challenge. Here, Li

Theoretical and experimental study of the bio-geochemical behaviour of americium 241 in simplified rhizosphere conditions. Application to a calcareous agricultural soil

International Nuclear Information System (INIS)

Perrier, T.

2004-06-01

Americium 241, is one of the most radio-toxic contaminant produced during the nuclear fuel cycle. It can be found in all environmental compartments, in particular the soils. The main goals of this study are to identify, quantify and model the effect of the main factors controlling the mobility of 241 Am in the rhizosphere and the agricultural soils. The physico-chemical parameters of the soil and of the soil solution, the potential role of microorganisms on the sorption-desorption processes, and the speciation of americium in solution have been more particularly studied. 241 Am remobilization has been studied at the laboratory using leaching experiments performed in controlled conditions on reworked calcareous soils artificially contaminated with 241 Am. The soil samples have been washed out in different hydrodynamic conditions by solutions with various compositions. The eluted solution has been analyzed (pH, conductivity, ionic composition, Fe tot , organic acids, 241 Am) and its bacterial biomass content too. The overall results indicate that 241 Am remobilization is contrasted and strongly linked with the condition under study (pH, ionic strength, glucose and/or citrate concentration). Therefore, a solution in equilibrium with the soil or containing small exudate concentrations (10 -4 M) re-mobilizes only a very small part of the americium fixed on the solid phase. The desorption of 241 Am corresponds to a solid/liquid coefficient of partition (K d ) of about 10 5 L.kg -1 . A significant addition of glucose induces an important dissolution of soil carbonates by the indirect action of microorganisms, but does not significantly favor the 241 Am remobilization. On the other hand, the presence of strong citrate concentrations (≥ 10 -2 M) allows 300 to 10000 time greater re-mobilizations by the complexing of 241 Am released after the dissolution of the carrying phases. Finally, the colloidal transport of 241 Am has been systematically observed in a limited but

Dynamics of production of iodine atoms by dissociation of iodides in a pulsed self-sustained discharge

International Nuclear Information System (INIS)

Vagin, Nikolai P; Kochetov, Igor' V; Napartovich, A P; Yuryshev, Nikolai N

2013-01-01

Absorption at the laser transition has been used for the first time to assess the evolution of concentration of iodine atoms in a pulsed self-sustained discharge in mixtures of iodides with a buffer gas such as molecular nitrogen and helium. Dynamics of the iodine atom production is studied by the method of absorption spectroscopy. The dissociation of C n F 2n+1 I and CnH 2n+1 I (n = 1, 2) iodides is investigated. The energy required to produce atomic iodine is evaluated. The experimental data obtained for CF 3 I are compared with the results of numerical simulations, their reasonable agreement being demonstrated. (active media)

Iodide selective membrane electrodes based on a Molybdenum-Salen as a neutral carrier

Energy Technology Data Exchange (ETDEWEB)

Ghanei-Motlagh, Masoud [Department of Chemistry, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Taher, Mohammad Ali, E-mail: ma_taher@yahoo.com [Department of Chemistry, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Ahmadi, Kyoumars [AJA University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sheikhshoaie, Iran [Department of Chemistry, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of)

2011-12-01

A new polymeric membrane electrode (PME) and a coated platinum disk electrode (CPtE) based on Schiff base complex of Mo(VI) as a suitable carrier for I{sup -} ion were described. The influence of membrane composition, pH and possible interfering anions were investigated on the response properties of the electrodes. The electrodes exhibited a Nernstian slope of 63.0 {+-} 0.5 (CPtE) and 60.3 {+-} 0.4 (PME) mV decade{sup -1} in I{sup -} ion over a wide concentration range from 7.9 x 10{sup -7} to 1.0 x 10{sup -1} M for CPtE and 9.1 x 10{sup -6} to 1.0 x 10{sup -1} M I{sup -} for PME. The potentiometric response of the electrodes was independent of the pH of the test solution in the pH range 2.0-8.5 with a fast response time (< 10 s). The process of transfer of iodide across the membrane interface was investigated by use of the AC impedance technique. The proposed sensors were successfully applied to direct determination of iodide in samples containing interfering anions, waste water and as indicator electrodes in precipitation titrations. Highlights: {yields} We study new selective membrane electrodes for iodide ions. {yields} To the best of our knowledge this is the first coated platinum disk electrode of I{sup -}. {yields} The sensors have a wide concentration range with a fast response time. {yields} Efforts have been made to improve the selectivity with the use of CPtE.

Charge Carrier Dynamics of Methylammonium Lead-Iodide Perovskite Solar Cells

OpenAIRE

Neukom, Martin Thomas

2016-01-01

Transient opto-electrical measurements of methylammonium lead iodide (MALI) perovskite solar cells (PSCs) are performed and analyzed in order to elucidate the operating mechanisms. The current response to a light pulse or voltage pulse shows an extraordinarily broad dynamic range covering 9 orders of magnitude in time - from microseconds to minutes - until steady-state is reached. Evidence of a slowly changing charge density at the perovskite layer boundaries is found, which is most probably ...

A colorimetric method for highly sensitive and accurate detection of iodide by finding the critical color in a color change process using silver triangular nanoplates

Energy Technology Data Exchange (ETDEWEB)

Yang, Xiu-Hua; Ling, Jian, E-mail: lingjian@ynu.edu.cn; Peng, Jun; Cao, Qiu-E., E-mail: qecao@ynu.edu.cn; Ding, Zhong-Tao; Bian, Long-Chun

2013-10-10

Graphical abstract: -- Highlights: •Demonstrated a new colorimetric strategy for iodide detection by silver nanoplates. •The colorimetric strategy is to find the critical color in a color change process. •The colorimetric strategy is more accurate and sensitive than common colorimetry. •Discovered a new morphological transformation phenomenon of silver nanoplates. -- Abstract: In this contribution, we demonstrated a novel colorimetric method for highly sensitive and accurate detection of iodide using citrate-stabilized silver triangular nanoplates (silver TNPs). Very lower concentration of iodide can induce an appreciable color change of silver TNPs solution from blue to yellow by fusing of silver TNPs to nanoparticles, as confirmed by UV–vis absorption spectroscopy and transmission electron microscopy (TEM). The principle of this colorimetric assay is not an ordinary colorimetry, but a new colorimetric strategy by finding the critical color in a color change process. With this strategy, 0.1 μM of iodide can be recognized within 30 min by naked-eyes observation, and lower concentration of iodide down to 8.8 nM can be detected using a spectrophotometer. Furthermore, this high sensitive colorimetric assay has good accuracy, stability and reproducibility comparing with other ordinary colorimetry. We believe this new colorimetric method will open up a fresh insight of simple, rapid and reliable detection of iodide and can find its future application in the biochemical analysis or clinical diagnosis.

A colorimetric method for highly sensitive and accurate detection of iodide by finding the critical color in a color change process using silver triangular nanoplates

International Nuclear Information System (INIS)

Yang, Xiu-Hua; Ling, Jian; Peng, Jun; Cao, Qiu-E.; Ding, Zhong-Tao; Bian, Long-Chun

2013-01-01

Graphical abstract: -- Highlights: •Demonstrated a new colorimetric strategy for iodide detection by silver nanoplates. •The colorimetric strategy is to find the critical color in a color change process. •The colorimetric strategy is more accurate and sensitive than common colorimetry. •Discovered a new morphological transformation phenomenon of silver nanoplates. -- Abstract: In this contribution, we demonstrated a novel colorimetric method for highly sensitive and accurate detection of iodide using citrate-stabilized silver triangular nanoplates (silver TNPs). Very lower concentration of iodide can induce an appreciable color change of silver TNPs solution from blue to yellow by fusing of silver TNPs to nanoparticles, as confirmed by UV–vis absorption spectroscopy and transmission electron microscopy (TEM). The principle of this colorimetric assay is not an ordinary colorimetry, but a new colorimetric strategy by finding the critical color in a color change process. With this strategy, 0.1 μM of iodide can be recognized within 30 min by naked-eyes observation, and lower concentration of iodide down to 8.8 nM can be detected using a spectrophotometer. Furthermore, this high sensitive colorimetric assay has good accuracy, stability and reproducibility comparing with other ordinary colorimetry. We believe this new colorimetric method will open up a fresh insight of simple, rapid and reliable detection of iodide and can find its future application in the biochemical analysis or clinical diagnosis

Radioiodine source term and its potential impact on the use of potassium iodide

International Nuclear Information System (INIS)

Malinauskas, A.P.

1982-01-01

Information is presented concerning chemical forms of fission product iodine in the primary circuit; chemical forms of fission product iodine in the containment building; summary of iodine chemistry in light water reactor accidents; and impact of the radiodine source term on the potassium iodide issue

Regioselective conversion of primary alcohols into iodides in unprotected methyl furanosides and pyranosides

DEFF Research Database (Denmark)

Skaanderup, Philip Robert; Poulsen, Carina Storm; Hyldtoft, Lene

2002-01-01

Two methods are described for the regioselective displacement of the primary hydroxy group in methyl glycosides with iodide. The first method is a modification of a literature procedure employing triphenylphosphine and iodine, where purification has been carried out on a reverse phase column in o...

Extension of HPM Pulse Duration by Cesium Iodide Cathodes in Crossed Field Devices

National Research Council Canada - National Science Library

Benford, James

1998-01-01

.... The introduction of cathodes made from Cesium Iodide-coated (CsI) carbon fiber has shown plasma speeds reduced by factors of a few from uncoated carbon fiber, but previous work was at low diode fields of a few 10's of kV/cm...

Experimental study of Americium-241 biokinetics in Homarus Gammarus lobster. Analysis of the accumulation and detoxication mechanisms at the sub-cellular level; Etude experimentale des biocinetiques de l`americium-241 chez le homard homarus gammarus. Analyse des mecanismes d`accumulation et de detoxication au niveau subcellulaire

Energy Technology Data Exchange (ETDEWEB)

Paquet, F

1991-12-01

The Americium 241 radioelement accumulation and elimination rate and mechanisms in the lobster organism have been experimentally studied; incorporation and detoxification capacities of each organ are evaluated. The existence of various biological compartments is shown; the major role of the digestive gland in accumulation of the radioelement, its distribution towards the various organs, and its resorption is comprehensively described, with an analysis at the subcellular and molecular levels. 401 p., 65 fig., 43 tab., 428 ref.

Monochloramine determination using NN diethyl-p-phenylene-diamine. Influence of iodide traces

International Nuclear Information System (INIS)

Fiquet, J.M.

1980-09-01

When determining ''D.P.D.'' free oxidizers, the monochloramine interfers in particular for iodide levels analogous to those likely to be found in sea water. This is not so for iodate. The zero time extrapolation of the change in colour curve is one method that enables the method to be made more selective [fr

Determination of iodide with 1,3-dibromo-5,5-dimethylhydantoin (DBH) in comparison with the ICl-method. Analytical methods of pharmacopeias with DBH in respect to environmental and economical concern. Part 3.

Science.gov (United States)

Hilp, M; Senjuk, S

2001-06-01

USP 1995 (The United States Pharmacopeia, 23rd Edit., (1995), potassium iodide p. 1265, sodium iodide p. 1424), PH. EUR. 1997 (European Pharmacopoeia, third ed., Council of Europe, Strasbourg, (1997), potassium iodide p. 1367, sodium iodide p. 1493) and JAP 1996 (The Japanes Pharmacopoeia, 13th ed. (1996), potassium iodide p. 578, sodium iodide p. 630) determine iodide with the ICl-method (J. Am. Chem. Soc. 25 (1903) 756-761; Z. Anorg. Chem. 36 (1903) 76-83; Fresenius Z. Anal. Chem. 106 (1936) 12-23; Arzneibuch-Kommentar, Wissenschaftliche Erläuterungen zum Europäischen Arzneibuch, Wissenschaftliche Verlagsgesellschaft mbH, Stuttgart, Govi-Verlag - Pharmazeutischer Verlag GmbH, Eschborn, 12th suppl. (1999), K10 p. 2), using chloroform, which is toxic and hazardous to environment. Without the application of chlorinated hydrocarbons USP 2000 (The United State Pharmacopeia, 24th ed. (2000), potassium iodide p. 1368, sodium iodide p. 1535) and Brit 1999 (British Pharmacopoeia London, (1999), Appendix VIII C, p. A162) titrate iodide with the redox indicator amaranth. A titration with potentiometric indication giving two end-points at the step of I(2) and [ICl(2)](-) is described. Due to the high concentration of hydrochloric acid required for the ICl-method, the determination with DBH (1,3-dibromo-5,5-dimethylhydantoin; 1,3-dibromo-5,5-dimethyl-2,4-imidazolidinedione) can be recommended and is performed easily. Similarly, the iodide content of gallamine triethiodide may be analyzed with DBH by application of a visual two-phase titration in water and ethyl acetate or with potentiometric indication in a mixture of 2-propanol and water. During the removal of the excess of DBH 4-bromo-triethylgallamine (2,2',2"-[1-bromo-benzene-2,3,4-triyltris(oxy)]N,N,N-triethylethanium) is formed.

AAO-CNTs electrode on microfluidic flow injection system for rapid iodide sensing.

Science.gov (United States)

Phokharatkul, Ditsayut; Karuwan, Chanpen; Lomas, Tanom; Nacapricha, Duangjai; Wisitsoraat, Anurat; Tuantranont, Adisorn

2011-06-15

In this work, carbon nanotubes (CNTs) nanoarrays in anodized aluminum oxide (AAO-CNTs) nanopore is integrated on a microfluidic flow injection system for in-channel electrochemical detection of iodide. The device was fabricated from PDMS (polydimethylsiloxane) microchannel bonded on glass substrates that contains three-electrode electrochemical system, including AAO-CNTs as a working electrode, silver as a reference electrode and platinum as an auxiliary electrode. Aluminum, stainless steel catalyst, silver and platinum layers were sputtered on the glass substrate through shadow masks. Aluminum layer was then anodized by two-step anodization process to form nanopore template. CNTs were then grown in AAO template by thermal chemical vapor deposition. The amperometric detection of iodide was performed in 500-μm-wide and 100-μm-deep microchannels on the microfluidic chip. The influences of flow rate, injection volume and detection potential on the current response were optimized. From experimental results, AAO-CNTs electrode on chip offers higher sensitivity and wider dynamic range than CNTs electrode with no AAO template. Copyright © 2011 Elsevier B.V. All rights reserved.

Solvent-Free Synthesis of Aryl Iodide Using Nano SiO2/HIO4 as a Reusable Acid Catalyst

Directory of Open Access Journals (Sweden)

A. Bamoniri

2014-07-01

Full Text Available An efficient and environmentally benign   method for the synthesis of aryl iodides have been developed by diazotization of aromatic amines with NaNO2 and nanosilica periodic acid (nano-SPIA as a green catalyst via grinding followed by a sandmeyer iodination by KI under solvent-free conditions at room temperature. The ensuing aryl diazonium salts supported on nano-SPIA were sufficiently stable to be kept at room temperature in the dry state. This method is a novel, efficient, eco-friendly route for solvent-free synthesis of aryl iodides.

Separation and measurement of thorium, plutonium, americium, uranium and strontium in environmental matrices

International Nuclear Information System (INIS)

Harrison, Jennifer J.; Zawadzki, Atun; Chisari, Robert; Wong, Henri K.Y.

2011-01-01

A technique for the isolation of thorium (Th), plutonium (Pu), americium (Am), uranium (U) and strontium (Sr) isotopes from various environmental matrices has been adapted from a previously published method specific to water samples (). Separation and isolation of the various elemental fractions from a single sub-sample is possible, thereby eliminating the need for multiple analyses. The technique involves sample dissolution, concentration via calcium phosphate co-precipitation, rapid column extraction using TEVA TM , TRU TM and Sr-Spec TM resin cartridges, alpha spectrometry for Th, Pu, U and Am and Cerenkov counting for Sr. Various standard reference materials were analysed and chemical yields are in the range of 70-80% for Th, Am, U and Sr and 50-60% for Pu. Sample sizes of up to 10 L for water, 5 g for dry soil and sediment and 10 g for dry vegetation and seaweed can be processed using this technique.

Solubility of plutonium and americium-241 from rumen contents of cattle grazing on plutonium-contaminated desert vegetation in in vitro bovine gastrointestinal fluids - August 1975 to January 1977

International Nuclear Information System (INIS)

Barth, J.; Giles, K.R.; Brown, K.W.

1985-01-01

The alimentary solubility of plutonium and americium-241 ingested by cattle grazing at Area 13 of the Nevada Test Site and the Clean Slate II site on the Tonopah Test Range in Nevada was studied in a series of experiments. For each experiment, or trial, rumen contents collected from a fistulated steer or a normal animals at the time of sacrifice were incubated in simulated bovine gastrointestinal fluids, and the solubility of plutonium and americium was analyzed following the abomasal, duodenal, jejunal, and lower intestinal digestive states. For Area 13, the peak plutonium-238 solubilities ranged from 1.09 to 9.60 percent for animals grazing in the inner enclosure that surrounds ground zero (GZ); for animals grazing in the outer enclosure, the peaks ranged from 1.86 to 18.46%. The peak plutonium-239 solubilities ranged from 0.71 to 4.81% for animals from the inner enclosure and from 0.71 to 3.61% for animals from the outer enclosure. Plutonium-238 was generally more soluble than plutonium-239. Plutonium ingested by cattle grazing in the outer enclosure was usually more soluble than plutonium ingested by cattle grazing in the inner enclosure. The highest concentrations of plutonium in the rumen contents of cattle grazing in the inner enclosure were found in trials conducted during August and November 1975 and January 1976. These concentrations decreased during the February, May, and July 1976 trials. The decrease was followed by an increase in plutonium concentration during the November 1976 trial. The concentration of americium-241 followed the same trend. 13 references, 13 tables

Ferroelastic Fingerprints in Methylammonium Lead Iodide Perovskite

KAUST Repository

Hermes, Ilka M.

2016-02-12

Methylammonium lead iodide (MAPbI3) perovskite materials show an outstanding performance in photovoltaic devices. However, certain material properties, especially the possible ferroic behavior, remain unclear. We observed distinct nanoscale periodic domains in the piezoresponse of MAPbI3(Cl) grains. The structure and the orientation of these striped domains indicate ferroelasticity as their origin. By correlating vertical and lateral piezoresponse force microscopy experiments performed at different sample orientations with x-ray diffraction, the preferred domain orientation was suggested to be the a1-a2-phase. The observation of these ferroelastic fingerprints appears to strongly depend on the film texture and thus the preparation route. The formation of the ferroelastic twin domains could be induced by internal strain during the cubic-tetragonal phase transition.

Inversion symmetry and bulk Rashba effect in methylammonium lead iodide perovskite single crystals

KAUST Repository

Frohna, Kyle

2018-05-02

Methylammonium lead iodide perovskite (MAPbI3) exhibits long charge carrier lifetimes that are linked to its high efficiency in solar cells. Yet, the mechanisms governing these unusual carrier dynamics are not completely understood. A leading hypothesis-disproved in this work-is that a large, static bulk Rashba effect slows down carrier recombination. Here, using second harmonic generation rotational anisotropy measurements on MAPbI3 crystals, we demonstrate that the bulk structure of tetragonal MAPbI3 is centrosymmetric with I4/mcm space group. Our calculations show that a significant Rashba splitting in the bandstructure requires a non-centrosymmetric lead iodide framework, and that incorrect structural relaxations are responsible for the previously predicted large Rashba effect. The small Rashba splitting allows us to compute effective masses in excellent agreement with experiment. Our findings rule out the presence of a large static Rashba effect in bulk MAPbI3, and our measurements find no evidence of dynamic Rashba effects.